CVE-2026-23276

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23276", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.991Z", "datePublished": "2026-03-20T08:08:56.575Z", "dateUpdated": "2026-11-05T21:33:34.931Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:39:04.913Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add xmit recursion limit to tunnel xmit functions\n\nTunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own\nrecursion limit. When a bond device in broadcast mode has GRE tap\ninterfaces as slaves, and those GRE tunnels route back through the\nbond, multicast/broadcast traffic triggers infinite recursion between\nbond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing\nkernel stack overflow.\n\nThe existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not\nsufficient because tunnel recursion involves route lookups and full IP\noutput, consuming much more stack per level. Use a lower limit of 4\n(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.\n\nAdd recursion detection using dev_xmit_recursion helpers directly in\niptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel\npaths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).\n\nMove dev_xmit_recursion helpers from net/core/dev.h to public header\ninclude/linux/netdevice.h so they can be used by tunnel code.\n\n BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160\n Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11\n Workqueue: mld mld_ifc_work\n Call Trace:\n <TASK>\n __build_flow_key.constprop.0 (net/ipv4/route.c:515)\n ip_rt_update_pmtu (net/ipv4/route.c:1073)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n mld_sendpack\n mld_ifc_work\n process_one_work\n worker_thread\n </TASK>"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "versions": [{"version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "da5f0166cef3d4285ddbb1b638661263fc03ee92", "status": "affected", "versionType": "git"}, {"version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "834c4f645726a25fd71ea50cdfb5c135f8f95d85", "status": "affected", "versionType": "git"}, {"version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "8a57deeb256069f262957d8012418559ff66c385", "status": "affected", "versionType": "git"}, {"version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "b56b8d19bd05e2a8338385c770bc2b60590bc81e", "status": "affected", "versionType": "git"}, {"version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "6f1a9140ecda3baba3d945b9a6155af4268aafc4", "status": "affected", "versionType": "git"}, {"version": "3f266b04185de51d8e6446eb1fccec3b5e7ce575", "status": "affected", "versionType": "git"}, {"version": "2.6.35.9", "lessThan": "2.6.36", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "versions": [{"version": "2.6.37", "status": "affected"}, {"version": "0", "lessThan": "2.6.37", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.9", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.12.78"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.18.19"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.19.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "7.0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35.9"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/da5f0166cef3d4285ddbb1b638661263fc03ee92"}, {"url": "https://git.kernel.org/stable/c/834c4f645726a25fd71ea50cdfb5c135f8f95d85"}, {"url": "https://git.kernel.org/stable/c/8a57deeb256069f262957d8012418559ff66c385"}, {"url": "https://git.kernel.org/stable/c/b56b8d19bd05e2a8338385c770bc2b60590bc81e"}, {"url": "https://git.kernel.org/stable/c/6f1a9140ecda3baba3d945b9a6155af4268aafc4"}], "title": "net: add xmit recursion limit to tunnel xmit functions", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-23276", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-05T21:24:42.961997Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-05T21:33:34.931Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-23276", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-05T21:24:42.961997Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-05T21:24:44.248Z"}}], "cna": {"title": "net: add xmit recursion limit to tunnel xmit functions", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "da5f0166cef3d4285ddbb1b638661263fc03ee92", "versionType": "git"}, {"status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "834c4f645726a25fd71ea50cdfb5c135f8f95d85", "versionType": "git"}, {"status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "8a57deeb256069f262957d8012418559ff66c385", "versionType": "git"}, {"status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "b56b8d19bd05e2a8338385c770bc2b60590bc81e", "versionType": "git"}, {"status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "lessThan": "6f1a9140ecda3baba3d945b9a6155af4268aafc4", "versionType": "git"}, {"status": "affected", "version": "3f266b04185de51d8e6446eb1fccec3b5e7ce575", "versionType": "git"}, {"status": "affected", "version": "2.6.35.9", "lessThan": "2.6.36", "versionType": "semver"}], "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "2.6.37"}, {"status": "unaffected", "version": "0", "lessThan": "2.6.37", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.160", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.78", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.19", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.9", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/da5f0166cef3d4285ddbb1b638661263fc03ee92"}, {"url": "https://git.kernel.org/stable/c/834c4f645726a25fd71ea50cdfb5c135f8f95d85"}, {"url": "https://git.kernel.org/stable/c/8a57deeb256069f262957d8012418559ff66c385"}, {"url": "https://git.kernel.org/stable/c/b56b8d19bd05e2a8338385c770bc2b60590bc81e"}, {"url": "https://git.kernel.org/stable/c/6f1a9140ecda3baba3d945b9a6155af4268aafc4"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add xmit recursion limit to tunnel xmit functions\n\nTunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own\nrecursion limit. When a bond device in broadcast mode has GRE tap\ninterfaces as slaves, and those GRE tunnels route back through the\nbond, multicast/broadcast traffic triggers infinite recursion between\nbond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing\nkernel stack overflow.\n\nThe existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not\nsufficient because tunnel recursion involves route lookups and full IP\noutput, consuming much more stack per level. Use a lower limit of 4\n(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.\n\nAdd recursion detection using dev_xmit_recursion helpers directly in\niptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel\npaths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).\n\nMove dev_xmit_recursion helpers from net/core/dev.h to public header\ninclude/linux/netdevice.h so they can be used by tunnel code.\n\n BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160\n Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11\n Workqueue: mld mld_ifc_work\n Call Trace:\n <TASK>\n __build_flow_key.constprop.0 (net/ipv4/route.c:515)\n ip_rt_update_pmtu (net/ipv4/route.c:1073)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n mld_sendpack\n mld_ifc_work\n process_one_work\n worker_thread\n </TASK>"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.160", "versionStartIncluding": "2.6.37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.78", "versionStartIncluding": "2.6.37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.19", "versionStartIncluding": "2.6.37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.19.9", "versionStartIncluding": "2.6.37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0", "versionStartIncluding": "2.6.37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "2.6.35.9"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:39:04.913Z"}}}, "cveMetadata": {"cveId": "CVE-2026-23276", "state": "PUBLISHED", "dateUpdated": "2026-11-05T21:33:34.931Z", "dateReserved": "2026-01-13T15:37:45.991Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-03-20T08:08:56.575Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "da5f0166cef3d4285ddbb1b638661263fc03ee92", "status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "versionType": "git"}, {"lessThan": "834c4f645726a25fd71ea50cdfb5c135f8f95d85", "status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "versionType": "git"}, {"lessThan": "8a57deeb256069f262957d8012418559ff66c385", "status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "versionType": "git"}, {"lessThan": "b56b8d19bd05e2a8338385c770bc2b60590bc81e", "status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "versionType": "git"}, {"lessThan": "6f1a9140ecda3baba3d945b9a6155af4268aafc4", "status": "affected", "version": "745e20f1b626b1be4b100af5d4bf7b3439392f8f", "versionType": "git"}, {"status": "affected", "version": "3f266b04185de51d8e6446eb1fccec3b5e7ce575", "versionType": "git"}, {"lessThan": "2.6.36", "status": "affected", "version": "2.6.35.9", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/linux/netdevice.h", "include/net/ip6_tunnel.h", "include/net/ip_tunnels.h", "net/core/dev.h", "net/ipv4/ip_tunnel_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.37"}, {"lessThan": "2.6.37", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.78", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.19", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "BB30F95D-9634-492E-93DE-1F7552FA5CB7", "versionEndExcluding": "2.6.36", "versionStartIncluding": "2.6.35.9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E97A7946-FFE5-4F91-86FB-DE0F43365250", "versionEndExcluding": "6.12.78", "versionStartIncluding": "2.6.37", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331", "versionEndExcluding": "6.18.19", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9", "versionEndExcluding": "6.19.9", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add xmit recursion limit to tunnel xmit functions\n\nTunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own\nrecursion limit. When a bond device in broadcast mode has GRE tap\ninterfaces as slaves, and those GRE tunnels route back through the\nbond, multicast/broadcast traffic triggers infinite recursion between\nbond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing\nkernel stack overflow.\n\nThe existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not\nsufficient because tunnel recursion involves route lookups and full IP\noutput, consuming much more stack per level. Use a lower limit of 4\n(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.\n\nAdd recursion detection using dev_xmit_recursion helpers directly in\niptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel\npaths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).\n\nMove dev_xmit_recursion helpers from net/core/dev.h to public header\ninclude/linux/netdevice.h so they can be used by tunnel code.\n\n BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160\n Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11\n Workqueue: mld mld_ifc_work\n Call Trace:\n <TASK>\n __build_flow_key.constprop.0 (net/ipv4/route.c:515)\n ip_rt_update_pmtu (net/ipv4/route.c:1073)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n mld_sendpack\n mld_ifc_work\n process_one_work\n worker_thread\n </TASK>"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: a\u00f1adir l\u00edmite de recursi\u00f3n de xmit a las funciones xmit de t\u00fanel\n\nLas funciones xmit de t\u00fanel (iptunnel_xmit, ip6tunnel_xmit) carecen de su propio l\u00edmite de recursi\u00f3n. Cuando un dispositivo bond en modo broadcast tiene interfaces GRE tap como esclavos, y esos t\u00faneles GRE enrutan de vuelta a trav\u00e9s del bond, el tr\u00e1fico multicast/broadcast desencadena una recursi\u00f3n infinita entre bond_xmit_broadcast() y ip_tunnel_xmit()/ip6_tnl_xmit(), causando un desbordamiento de pila del kernel.\n\nEl XMIT_RECURSION_LIMIT (8) existente en la ruta sin qdisc no es suficiente porque la recursi\u00f3n del t\u00fanel implica b\u00fasquedas de ruta y salida IP completa, consumiendo mucha m\u00e1s pila por nivel. Use un l\u00edmite inferior de 4 (IP_TUNNEL_RECURSION_LIMIT) para prevenir el desbordamiento.\n\nA\u00f1ada detecci\u00f3n de recursi\u00f3n usando las funciones auxiliares dev_xmit_recursion directamente en iptunnel_xmit() y ip6tunnel_xmit() para cubrir todas las rutas de t\u00fanel IPv4/IPv6, incluyendo los t\u00faneles encapsulados UDP (VXLAN, Geneve, etc.).\n\nMueva las funciones auxiliares dev_xmit_recursion de net/core/dev.h al encabezado p\u00fablico include/linux/netdevice.h para que puedan ser usadas por el c\u00f3digo del t\u00fanel.\n\nBUG: KASAN: pila-fuera-de-l\u00edmites en blake2s.constprop.0+0xe7/0x160\nEscritura de tama\u00f1o 32 en la direcci\u00f3n ffff88810033fed0 por la tarea kworker/0:1/11\nCola de trabajo: mld mld_ifc_work\nRastro de Llamada:\n \n __build_flow_key.constprop.0 (net/ipv4/route.c:515)\n ip_rt_update_pmtu (net/ipv4/route.c:1073)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n ip_finish_output2 (net/ipv4/ip_output.c:237)\n ip_output (net/ipv4/ip_output.c:438)\n iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n gre_tap_xmit (net/ipv4/ip_gre.c:779)\n dev_hard_start_xmit (net/core/dev.c:3887)\n sch_direct_xmit (net/sched/sch_generic.c:347)\n __dev_queue_xmit (net/core/dev.c:4802)\n bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n dev_hard_start_xmit (net/core/dev.c:3887)\n __dev_queue_xmit (net/core/dev.c:4841)\n mld_sendpack\n mld_ifc_work\n process_one_work\n worker_thread\n "}], "id": "CVE-2026-23276", "lastModified": "2026-11-05T22:18:10.813", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-23276", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-11-05T21:24:42.961997Z", "version": "2.0.3"}}]}, "published": "2026-03-20T09:16:13.370", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6f1a9140ecda3baba3d945b9a6155af4268aafc4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/834c4f645726a25fd71ea50cdfb5c135f8f95d85"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8a57deeb256069f262957d8012418559ff66c385"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b56b8d19bd05e2a8338385c770bc2b60590bc81e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/da5f0166cef3d4285ddbb1b638661263fc03ee92"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-674"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: net: add xmit recursion limit to tunnel xmit functions", "id": "2449561", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2449561"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-835", "details": ["A flaw was found in the Linux kernel. When a bond device in broadcast mode has Generic Routing Encapsulation (GRE) tap interfaces configured as slaves, and these GRE tunnels are routed back through the bond, multicast or broadcast network traffic can trigger an infinite recursion. This recursion occurs within the kernel's tunnel transmit functions, leading to a kernel stack overflow. A local attacker could potentially exploit this to cause a Denial of Service (DoS) on the system."], "mitigation": {"lang": "en:us", "value": "Avoid configuring bond devices in broadcast mode with tunnel interfaces (GRE, VXLAN, Geneve) as slaves when those tunnels route back through the bond. Alternatively, use a different bonding mode such as active-backup or 802.3ad."}, "name": "CVE-2026-23276", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-03-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-23276\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23276\nhttps://lore.kernel.org/linux-cve-announce/2026032035-CVE-2026-23276-7fd3@gregkh/T"], "statement": "This vulnerability requires a specific network configuration: a bonding device in broadcast mode with GRE tap tunnel slaves where the tunnels route back through the bond. When multicast or broadcast traffic is sent, the lack of recursion limits in tunnel transmit functions causes infinite recursion between bond_xmit_broadcast() and tunnel xmit functions, exhausting the kernel stack. This affects GRE, VXLAN, Geneve, and similar tunnels.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[745e20f1b626b1be4b100af5d4bf7b3439392f8f,8a57deeb256069f262957d8012418559ff66c385)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[745e20f1b626b1be4b100af5d4bf7b3439392f8f,b56b8d19bd05e2a8338385c770bc2b60590bc81e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[745e20f1b626b1be4b100af5d4bf7b3439392f8f,6f1a9140ecda3baba3d945b9a6155af4268aafc4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "3f266b04185de51d8e6446eb1fccec3b5e7ce575"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.37"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,2.6.37)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.19,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.19.9,6.19.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0-rc4,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-03-20T10:36:43.423549+00:00", "updated": "2026-05-26T15:45:08.886980+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}