CVE-2026-98852

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98852", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.376Z", "datePublished": "2026-10-18T15:50:55.946Z", "dateUpdated": "2026-10-21T12:57:32.027Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:57:32.027Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: extend IPv6 exthdr detection of tunneled packets\n\nCommit c4336a07eb6b (\"net: correctly handle tunneled traffic on IPV6_CSUM\nGSO fallback\") split skb_gso_has_extension_hdr() into mutually exclusive\nbranches on skb->encapsulation. This did not yet address all paths:\n\n1. With skb->encapsulation set, the outer header is not checked. IPv6\n tunnels such as ip6_gre and ip6_tunnel add an outer Destination\n Options header by default (encap_limit). Their GSO packets skip\n software GSO, then skb_csum_hwoffload_help() sees the outer extension\n header and calls skb_checksum_help() on the GSO skb, which warns and\n drops it.\n\n2. Tunnels over IPv6 without an outer transport header, such as\n ip6_tunnel, leave skb->transport_header at the inner transport\n header. skb_network_header_len() then spans the outer IPv6, tunnel\n and inner IP headers, a false positive.\n\n3. UDP tunnels without an inner network header, such as SCTP-in-UDP or\n PSP, have no inner IPv6 header to check. Decide on the outer header\n alone.\n\n4. Directly dereferencing inner_ip_hdr(skb)->version without\n skb_header_pointer() is unsafe.\n\nInstead, check ipv6_ext_hdr(nexthdr) on the outer IPv6 header and, if\nset, on the inner IPv6 header. Read the headers with skb_header_pointer().\nKeep the skb_network_header_len() check when !skb->encapsulation to also\ncatch encapsulated packets without skb->encapsulation (e.g., virtio).\n\nUse the same helper in skb_csum_hwoffload_help(). Its open coded test\nhas the false positive of (2) and ignores the inner header.\n\nBackground: checksum offload of tunneled packets invariants:\n\nNon-GSO skb:\n- If the inner packet is CHECKSUM_PARTIAL, Local Checksum Offload computes\n the outer checksum in software and the device offloads only the inner L4\n checksum.\n- If the inner packet is CHECKSUM_NONE (e.g., SCTP-in-UDP, ESP-in-UDP,\n Remote Checksum Offload), the device offloads the outer UDP or GRE\n checksum instead.\n\nGSO skb:\n- A device with NETIF_F_GSO_UDP_TUNNEL_CSUM or NETIF_F_GSO_GRE_CSUM\n computes both inner and outer checksums per segment.\n The outer checksum is seeded with only the pseudo-header checksum.\n\nA NETIF_F_IPV6_CSUM device must parse through the outer headers to\nreach the inner ones."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/core/dev.c"], "versions": [{"version": "ed71cf465c75f5688b07a35d373cd1d6b589c8ea", "lessThan": "fdbd83c2d929ec968b37d2f75149a79440e328ff", "status": "affected", "versionType": "git"}, {"version": "33670f780e0120c3dacda188c512bbffe0b6044c", "lessThan": "44ba9dc568c878b699d05e7cf699572dc9df4b59", "status": "affected", "versionType": "git"}, {"version": "a98b78116a27e2a57b696b569b2cb431c95cf9b6", "lessThan": "aa480f05aed7a9eee87d4a6fc90647fe9679c670", "status": "affected", "versionType": "git"}, {"version": "c4336a07eb6b2526dc2b62928b5104b41a7f81f5", "lessThan": "cabacdf98e09eb74599c4d97d7bd7fd659598fb7", "status": "affected", "versionType": "git"}, {"version": "c4336a07eb6b2526dc2b62928b5104b41a7f81f5", "lessThan": "5f0764cb1c81a9712bce605d38efe6d844a70b29", "status": "affected", "versionType": "git"}, {"version": "2094a7cf91b71367b649f991aacc7b579f793d0b", "status": "affected", "versionType": "git"}, {"version": "732fdeb2987c94b439d51f5cb9addddc2fc48c42", "status": "affected", "versionType": "git"}, {"version": "6.6.134", "lessThan": "6.6.160", "status": "affected", "versionType": "semver"}, {"version": "6.12.81", "lessThan": "6.12.113", "status": "affected", "versionType": "semver"}, {"version": "6.18.22", "lessThan": "6.18.56", "status": "affected", "versionType": "semver"}, {"version": "6.1.168", "lessThan": "6.2", "status": "affected", "versionType": "semver"}, {"version": "6.19.12", "lessThan": "6.20", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/core/dev.c"], "versions": [{"version": "7.0", "status": "affected"}, {"version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.56", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.10", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.6.134", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.81", "versionEndExcluding": "6.12.113"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.22", "versionEndExcluding": "6.18.56"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.2.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.168"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.12"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/fdbd83c2d929ec968b37d2f75149a79440e328ff"}, {"url": "https://git.kernel.org/stable/c/44ba9dc568c878b699d05e7cf699572dc9df4b59"}, {"url": "https://git.kernel.org/stable/c/aa480f05aed7a9eee87d4a6fc90647fe9679c670"}, {"url": "https://git.kernel.org/stable/c/cabacdf98e09eb74599c4d97d7bd7fd659598fb7"}, {"url": "https://git.kernel.org/stable/c/5f0764cb1c81a9712bce605d38efe6d844a70b29"}], "title": "net: extend IPv6 exthdr detection of tunneled packets", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/core/dev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "fdbd83c2d929ec968b37d2f75149a79440e328ff", "status": "affected", "version": "ed71cf465c75f5688b07a35d373cd1d6b589c8ea", "versionType": "git"}, {"lessThan": "44ba9dc568c878b699d05e7cf699572dc9df4b59", "status": "affected", "version": "33670f780e0120c3dacda188c512bbffe0b6044c", "versionType": "git"}, {"lessThan": "aa480f05aed7a9eee87d4a6fc90647fe9679c670", "status": "affected", "version": "a98b78116a27e2a57b696b569b2cb431c95cf9b6", "versionType": "git"}, {"lessThan": "cabacdf98e09eb74599c4d97d7bd7fd659598fb7", "status": "affected", "version": "c4336a07eb6b2526dc2b62928b5104b41a7f81f5", "versionType": "git"}, {"lessThan": "5f0764cb1c81a9712bce605d38efe6d844a70b29", "status": "affected", "version": "c4336a07eb6b2526dc2b62928b5104b41a7f81f5", "versionType": "git"}, {"status": "affected", "version": "2094a7cf91b71367b649f991aacc7b579f793d0b", "versionType": "git"}, {"status": "affected", "version": "732fdeb2987c94b439d51f5cb9addddc2fc48c42", "versionType": "git"}, {"lessThan": "6.6.160", "status": "affected", "version": "6.6.134", "versionType": "semver"}, {"lessThan": "6.12.113", "status": "affected", "version": "6.12.81", "versionType": "semver"}, {"lessThan": "6.18.56", "status": "affected", "version": "6.18.22", "versionType": "semver"}, {"lessThan": "6.2", "status": "affected", "version": "6.1.168", "versionType": "semver"}, {"lessThan": "6.20", "status": "affected", "version": "6.19.12", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/core/dev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.0"}, {"lessThan": "7.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.113", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.56", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: extend IPv6 exthdr detection of tunneled packets\n\nCommit c4336a07eb6b (\"net: correctly handle tunneled traffic on IPV6_CSUM\nGSO fallback\") split skb_gso_has_extension_hdr() into mutually exclusive\nbranches on skb->encapsulation. This did not yet address all paths:\n\n1. With skb->encapsulation set, the outer header is not checked. IPv6\n tunnels such as ip6_gre and ip6_tunnel add an outer Destination\n Options header by default (encap_limit). Their GSO packets skip\n software GSO, then skb_csum_hwoffload_help() sees the outer extension\n header and calls skb_checksum_help() on the GSO skb, which warns and\n drops it.\n\n2. Tunnels over IPv6 without an outer transport header, such as\n ip6_tunnel, leave skb->transport_header at the inner transport\n header. skb_network_header_len() then spans the outer IPv6, tunnel\n and inner IP headers, a false positive.\n\n3. UDP tunnels without an inner network header, such as SCTP-in-UDP or\n PSP, have no inner IPv6 header to check. Decide on the outer header\n alone.\n\n4. Directly dereferencing inner_ip_hdr(skb)->version without\n skb_header_pointer() is unsafe.\n\nInstead, check ipv6_ext_hdr(nexthdr) on the outer IPv6 header and, if\nset, on the inner IPv6 header. Read the headers with skb_header_pointer().\nKeep the skb_network_header_len() check when !skb->encapsulation to also\ncatch encapsulated packets without skb->encapsulation (e.g., virtio).\n\nUse the same helper in skb_csum_hwoffload_help(). Its open coded test\nhas the false positive of (2) and ignores the inner header.\n\nBackground: checksum offload of tunneled packets invariants:\n\nNon-GSO skb:\n- If the inner packet is CHECKSUM_PARTIAL, Local Checksum Offload computes\n the outer checksum in software and the device offloads only the inner L4\n checksum.\n- If the inner packet is CHECKSUM_NONE (e.g., SCTP-in-UDP, ESP-in-UDP,\n Remote Checksum Offload), the device offloads the outer UDP or GRE\n checksum instead.\n\nGSO skb:\n- A device with NETIF_F_GSO_UDP_TUNNEL_CSUM or NETIF_F_GSO_GRE_CSUM\n computes both inner and outer checksums per segment.\n The outer checksum is seeded with only the pseudo-header checksum.\n\nA NETIF_F_IPV6_CSUM device must parse through the outer headers to\nreach the inner ones."}], "id": "CVE-2026-98852", "lastModified": "2026-10-21T13:21:49.790", "metrics": {}, "published": "2026-10-18T16:17:39.593", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/44ba9dc568c878b699d05e7cf699572dc9df4b59"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5f0764cb1c81a9712bce605d38efe6d844a70b29"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/aa480f05aed7a9eee87d4a6fc90647fe9679c670"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cabacdf98e09eb74599c4d97d7bd7fd659598fb7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fdbd83c2d929ec968b37d2f75149a79440e328ff"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net: extend IPv6 exthdr detection of tunneled packets", "id": "2555240", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2555240"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet: extend IPv6 exthdr detection of tunneled packets\nCommit c4336a07eb6b (\"net: correctly handle tunneled traffic on IPV6_CSUM\nGSO fallback\") split skb_gso_has_extension_hdr() into mutually exclusive\nbranches on skb->encapsulation. This did not yet address all paths:\n1. With skb->encapsulation set, the outer header is not checked. IPv6\ntunnels such as ip6_gre and ip6_tunnel add an outer Destination\nOptions header by default (encap_limit). Their GSO packets skip\nsoftware GSO, then skb_csum_hwoffload_help() sees the outer extension\nheader and calls skb_checksum_help() on the GSO skb, which warns and\ndrops it.\n2. Tunnels over IPv6 without an outer transport header, such as\nip6_tunnel, leave skb->transport_header at the inner transport\nheader. skb_network_header_len() then spans the outer IPv6, tunnel\nand inner IP headers, a false positive.\n3. UDP tunnels without an inner network header, such as SCTP-in-UDP or\nPSP, have no inner IPv6 header to check. Decide on the outer header\nalone.\n4. Directly dereferencing inner_ip_hdr(skb)->version without\nskb_header_pointer() is unsafe.\nInstead, check ipv6_ext_hdr(nexthdr) on the outer IPv6 header and, if\nset, on the inner IPv6 header. Read the headers with skb_header_pointer().\nKeep the skb_network_header_len() check when !skb->encapsulation to also\ncatch encapsulated packets without skb->encapsulation (e.g., virtio).\nUse the same helper in skb_csum_hwoffload_help(). Its open coded test\nhas the false positive of (2) and ignores the inner header.\nBackground: checksum offload of tunneled packets invariants:\nNon-GSO skb:\n- If the inner packet is CHECKSUM_PARTIAL, Local Checksum Offload computes\nthe outer checksum in software and the device offloads only the inner L4\nchecksum.\n- If the inner packet is CHECKSUM_NONE (e.g., SCTP-in-UDP, ESP-in-UDP,\nRemote Checksum Offload), the device offloads the outer UDP or GRE\nchecksum instead.\nGSO skb:\n- A device with NETIF_F_GSO_UDP_TUNNEL_CSUM or NETIF_F_GSO_GRE_CSUM\ncomputes both inner and outer checksums per segment.\nThe outer checksum is seeded with only the pseudo-header checksum.\nA NETIF_F_IPV6_CSUM device must parse through the outer headers to\nreach the inner ones.", "A flaw was found in the Linux kernel's networking subsystem. An attacker could exploit this vulnerability by sending specially crafted encapsulated IPv6 network traffic, leading to a Denial of Service (DoS). This issue stems from improper validation and parsing of IPv6 extension headers in tunneled packets, which can cause network packet drops or trigger unsafe memory dereferences leading to system instability."], "name": "CVE-2026-98852", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-98852\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-98852\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98852.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[33670f780e0120c3dacda188c512bbffe0b6044c,44ba9dc568c878b699d05e7cf699572dc9df4b59)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a98b78116a27e2a57b696b569b2cb431c95cf9b6,aa480f05aed7a9eee87d4a6fc90647fe9679c670)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c4336a07eb6b2526dc2b62928b5104b41a7f81f5,cabacdf98e09eb74599c4d97d7bd7fd659598fb7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c4336a07eb6b2526dc2b62928b5104b41a7f81f5,5f0764cb1c81a9712bce605d38efe6d844a70b29)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "2094a7cf91b71367b649f991aacc7b579f793d0b"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "ed71cf465c75f5688b07a35d373cd1d6b589c8ea"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "732fdeb2987c94b439d51f5cb9addddc2fc48c42"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.12.81,6.12.113)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.18.22,6.18.56)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.1.168,6.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.134,6.7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.19.12,6.20)"}}], "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": "generic", "value": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.113,6.13.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.56,6.19.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.10,7.3.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "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": "2026-10-18T21:15:14.282505+00:00", "updated": "2026-10-24T04:45:16.966209+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}