CVE-2026-97420

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-97420", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T14:53:16.868Z", "datePublished": "2026-09-24T16:03:30.084Z", "dateUpdated": "2026-10-03T10:58:12.202Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-03T10:58:12.202Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: NUL-terminate replaced sysctl value\n\nWhen writing to sysctls, proc_sys_call_handler() guarantees that the\nbuffer passed to proc handlers is NUL-terminated. If\nbpf_sysctl_set_new_value() replaces the pending sysctl value, it can\nhand a replacement buffer directly to proc handlers. However, the\nhelper currently copies only buf_len bytes into that buffer without\nappending a NUL terminator, leaving downstream parsers vulnerable to\nout-of-bounds access.\n\nFix this by appending a '\\0' after the replaced value to restore the\nexpected sysctl semantics. Since the helper already rejects buf_len\ngreater than PAGE_SIZE - 1, there is always room for the extra byte.\n\nReproduced in a QEMU x86_64 guest booted with KASAN while exercising\nthe sysctl replacement path with a cgroup/sysctl BPF program. The\nreproducer targets `/proc/sys/net/core/flow_limit_cpu_bitmap`, fills\nthe original user write buffer with non-zero bytes, and overrides the\nsysctl value so the replacement buffer lacks a terminating NUL. Under\nthat setup, the pre-fix kernel reported:\n\n BUG: KASAN: slab-out-of-bounds in strnchrnul+0x72/0x90\n Read of size 1 at addr ffff88800de57000 by task repro_patch3/66\n CPU: 0 UID: 0 PID: 66 Comm: repro_patch3 Not tainted 7.1.0-rc3-00269-g8370ca1f87cc #6 PREEMPT(lazy)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n Call Trace:\n <TASK>\n dump_stack_lvl+0x68/0xa0\n print_report+0xcb/0x5e0\n ? __virt_addr_valid+0x21d/0x3f0\n ? strnchrnul+0x72/0x90\n ? strnchrnul+0x72/0x90\n kasan_report+0xca/0x100\n ? strnchrnul+0x72/0x90\n strnchrnul+0x72/0x90\n bitmap_parse+0x37/0x2e0\n flow_limit_cpu_sysctl+0xc6/0x840\n ? __pfx_flow_limit_cpu_sysctl+0x10/0x10\n ? __kvmalloc_node_noprof+0x5ba/0x870\n proc_sys_call_handler+0x31d/0x480\n ? __pfx_proc_sys_call_handler+0x10/0x10\n ? selinux_file_permission+0x39f/0x500\n ? lock_is_held_type+0x9e/0x120\n vfs_write+0x98e/0x1000\n ...\n </TASK>\n The buggy address is located 0 bytes to the right of\n allocated 4096-byte region [ffff88800de56000, ffff88800de57000)\nWith this fix applied, rerunning the same sysctl-targeted path yields\nno corresponding KASAN reports."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/cgroup.c"], "versions": [{"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "bfcee1f79aaefa90679ad47690107fb7682724ec", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "c73e4a04eedc677fe91a736d7a5db45100adba5e", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "36d3e9f62dc2beb9299d3bb6f589cb9e07f773fe", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "31377675c3d75603d957c08e338a9ac27e9f6cd5", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "76c14b10f50eb0afcc76e244562fa2d8c661e224", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "3b2814dd842a565fcf9cc370156e1ba9eae16239", "status": "affected", "versionType": "git"}, {"version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "lessThan": "a66e3b5bacf38d6ab29fa05a9754f7a114485605", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/cgroup.c"], "versions": [{"version": "5.8", "status": "affected"}, {"version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.8", "versionEndExcluding": "5.10.271"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.15.222"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bfcee1f79aaefa90679ad47690107fb7682724ec"}, {"url": "https://git.kernel.org/stable/c/c73e4a04eedc677fe91a736d7a5db45100adba5e"}, {"url": "https://git.kernel.org/stable/c/36d3e9f62dc2beb9299d3bb6f589cb9e07f773fe"}, {"url": "https://git.kernel.org/stable/c/31377675c3d75603d957c08e338a9ac27e9f6cd5"}, {"url": "https://git.kernel.org/stable/c/76c14b10f50eb0afcc76e244562fa2d8c661e224"}, {"url": "https://git.kernel.org/stable/c/3b2814dd842a565fcf9cc370156e1ba9eae16239"}, {"url": "https://git.kernel.org/stable/c/a66e3b5bacf38d6ab29fa05a9754f7a114485605"}], "title": "bpf: NUL-terminate replaced sysctl value", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/bpf/cgroup.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bfcee1f79aaefa90679ad47690107fb7682724ec", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "c73e4a04eedc677fe91a736d7a5db45100adba5e", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "36d3e9f62dc2beb9299d3bb6f589cb9e07f773fe", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "31377675c3d75603d957c08e338a9ac27e9f6cd5", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "76c14b10f50eb0afcc76e244562fa2d8c661e224", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "3b2814dd842a565fcf9cc370156e1ba9eae16239", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}, {"lessThan": "a66e3b5bacf38d6ab29fa05a9754f7a114485605", "status": "affected", "version": "32927393dc1ccd60fb2bdc05b9e8e88753761469", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/bpf/cgroup.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.8"}, {"lessThan": "5.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.271", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.222", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.189", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "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\nbpf: NUL-terminate replaced sysctl value\n\nWhen writing to sysctls, proc_sys_call_handler() guarantees that the\nbuffer passed to proc handlers is NUL-terminated. If\nbpf_sysctl_set_new_value() replaces the pending sysctl value, it can\nhand a replacement buffer directly to proc handlers. However, the\nhelper currently copies only buf_len bytes into that buffer without\nappending a NUL terminator, leaving downstream parsers vulnerable to\nout-of-bounds access.\n\nFix this by appending a '\\0' after the replaced value to restore the\nexpected sysctl semantics. Since the helper already rejects buf_len\ngreater than PAGE_SIZE - 1, there is always room for the extra byte.\n\nReproduced in a QEMU x86_64 guest booted with KASAN while exercising\nthe sysctl replacement path with a cgroup/sysctl BPF program. The\nreproducer targets `/proc/sys/net/core/flow_limit_cpu_bitmap`, fills\nthe original user write buffer with non-zero bytes, and overrides the\nsysctl value so the replacement buffer lacks a terminating NUL. Under\nthat setup, the pre-fix kernel reported:\n\n BUG: KASAN: slab-out-of-bounds in strnchrnul+0x72/0x90\n Read of size 1 at addr ffff88800de57000 by task repro_patch3/66\n CPU: 0 UID: 0 PID: 66 Comm: repro_patch3 Not tainted 7.1.0-rc3-00269-g8370ca1f87cc #6 PREEMPT(lazy)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n Call Trace:\n <TASK>\n dump_stack_lvl+0x68/0xa0\n print_report+0xcb/0x5e0\n ? __virt_addr_valid+0x21d/0x3f0\n ? strnchrnul+0x72/0x90\n ? strnchrnul+0x72/0x90\n kasan_report+0xca/0x100\n ? strnchrnul+0x72/0x90\n strnchrnul+0x72/0x90\n bitmap_parse+0x37/0x2e0\n flow_limit_cpu_sysctl+0xc6/0x840\n ? __pfx_flow_limit_cpu_sysctl+0x10/0x10\n ? __kvmalloc_node_noprof+0x5ba/0x870\n proc_sys_call_handler+0x31d/0x480\n ? __pfx_proc_sys_call_handler+0x10/0x10\n ? selinux_file_permission+0x39f/0x500\n ? lock_is_held_type+0x9e/0x120\n vfs_write+0x98e/0x1000\n ...\n </TASK>\n The buggy address is located 0 bytes to the right of\n allocated 4096-byte region [ffff88800de56000, ffff88800de57000)\nWith this fix applied, rerunning the same sysctl-targeted path yields\nno corresponding KASAN reports."}], "id": "CVE-2026-97420", "lastModified": "2026-10-03T11:17:54.123", "metrics": {}, "published": "2026-09-24T17:17:19.853", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/31377675c3d75603d957c08e338a9ac27e9f6cd5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/36d3e9f62dc2beb9299d3bb6f589cb9e07f773fe"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3b2814dd842a565fcf9cc370156e1ba9eae16239"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/76c14b10f50eb0afcc76e244562fa2d8c661e224"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a66e3b5bacf38d6ab29fa05a9754f7a114485605"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bfcee1f79aaefa90679ad47690107fb7682724ec"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c73e4a04eedc677fe91a736d7a5db45100adba5e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: bpf: NUL-terminate replaced sysctl value", "id": "2540519", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2540519"}, "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-125", "details": ["A flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) subsystem. When a BPF program modifies a system control (sysctl) parameter, the kernel fails to append a null-terminating byte to the replacement buffer. Downstream kernel parsers expecting a properly terminated string may read past the buffer boundary, resulting in an out-of-bounds memory access. A local user could exploit this flaw to cause a Denial of Service (DoS) through a system crash or potentially access sensitive kernel memory."], "name": "CVE-2026-97420", "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"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-97420\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-97420\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97420.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,76c14b10f50eb0afcc76e244562fa2d8c661e224)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,3b2814dd842a565fcf9cc370156e1ba9eae16239)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,a66e3b5bacf38d6ab29fa05a9754f7a114485605)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.12.111)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.18.53)"}}], "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": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.111,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.53,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "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": "2026-09-24T22:00:19.926145+00:00", "updated": "2026-10-01T16:45:09.981073+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}