{"id":"CVE-2026-72423","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Guard conntrack opts error writes\n\nThe conntrack lookup and allocation kfuncs take an opts pointer\ntogether with an opts__sz argument","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Guard conntrack opts error writes\n\nThe conntrack lookup and allocation kfuncs take an opts pointer\ntogether with an opts__sz argument. The verifier checks only the…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= b4c2b9593a1c4c3a718370e34af28e817fd5e5c6 < 453f4f1e90de55b6bc297936031b68bef93f2e28","Linux >= b4c2b9593a1c4c3a718370e34af28e817fd5e5c6 < dd74c80203842a21b2ebb9f70d1260d9aa20fa05","Linux >= b4c2b9593a1c4c3a718370e34af28e817fd5e5c6 < 6f6183a39533d727deaa5061cadae6dd9e6744d0","Linux 5.18"],"published":"2026-08-15","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:43.567","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72423","references":[{"url":"https://git.kernel.org/stable/c/453f4f1e90de55b6bc297936031b68bef93f2e28","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6f6183a39533d727deaa5061cadae6dd9e6744d0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dd74c80203842a21b2ebb9f70d1260d9aa20fa05","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72423.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-72423"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2516305"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72423"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72423"},{"url":"https://lore.kernel.org/linux-cve-announce/2026081526-CVE-2026-72423-9fac@gregkh/T"},{"url":"https://git.kernel.org/stable/c/669bc3b345712112d3f033a1953f5a10b15e7c65"},{"url":"https://git.kernel.org/stable/c/63d95c6bbd6fc0e411404188306a1fea456300b0"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00175,"epssPercentile":0.06967,"ingestedAt":"2026-10-15T11:00:41.685Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:49:41.501757Z"},"cwe":["CWE-787"],"scores":{"nvd":8.8,"vendor":5.5,"cna":8.8},"slug":"CVE-2026-72423","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Guard conntrack opts error writes\n\nThe conntrack lookup and allocation kfuncs take an opts pointer\ntogether with an opts__sz argument. The verifier checks only the memory\nrange described by opts__sz, but the wrappers unconditionally write\nopts->error whenever the internal lookup or allocation helper returns an\nerror.\n\nFor an invalid size smaller than the end of opts->error, that write can\nland outside the verifier-checked range. Keep returning NULL for invalid\narguments, but only report the error through opts->error when the\nsupplied size includes the field.\n\nThis preserves error reporting for the supported 12-byte and 16-byte\nlayouts, and for other invalid sizes that still include opts->error.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72423.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}