{"id":"CVE-2026-53246","state":"PUBLISHED","title":"sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate cached peer INIT chunk length in COOKIE_ECHO processing\n\nWhen a listening SCTP server processes a COOKIE_ECHO chunk, the cached\npeer INIT chunk embedded after the cookie is parsed and its parameters\nare later walked by sctp_process_init() using sctp_walk_params().\n\nHowever, the chunk header length of this cached INIT chunk was not\nvalidated against the remaining buffer in the COOKIE_ECHO payload. If\nthe length field is inflated, the parameter walk can run beyond the\nactual received data, leading to out-of-bounds reads and potential\nmemory corruption during later parameter handling (e.g. STATE_COOKIE\nprocessing and kmemdup() copies).\n\nAdd a bounds check in sctp_unpack_cookie() to ensure the cached INIT\nchunk length does not exceed the available data in the COOKIE_ECHO\nbuffer before it is used.","publishedAt":"2026-06-25T08:39:39.896Z","updatedAt":"2026-10-19T19:57:31.408Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"cc272185c9a9a4b7febc2de52eeaa3d00f19091e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"edccbf3d63b0a3362bc916ea72edacc1e1ca456a","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0861615c28de668669d748ef4eb913ea9262d13b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/sm_make_chunk.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/sm_make_chunk.c"]}],"references":["https://git.kernel.org/stable/c/cc272185c9a9a4b7febc2de52eeaa3d00f19091e","https://git.kernel.org/stable/c/edccbf3d63b0a3362bc916ea72edacc1e1ca456a","https://git.kernel.org/stable/c/0861615c28de668669d748ef4eb913ea9262d13b"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53246.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53246","state":"PUBLISHED","datePublished":"2026-06-25T08:39:39.896Z","dateUpdated":"2026-10-19T19:57:31.408Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.394Z"},"containers":{"cna":{"title":"sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate cached peer INIT chunk length in COOKIE_ECHO processing\n\nWhen a listening SCTP server processes a COOKIE_ECHO chunk, the cached\npeer INIT chunk embedded after the cookie is parsed and its parameters\nare later walked by sctp_process_init() using sctp_walk_params().\n\nHowever, the chunk header length of this cached INIT chunk was not\nvalidated against the remaining buffer in the COOKIE_ECHO payload. If\nthe length field is inflated, the parameter walk can run beyond the\nactual received data, leading to out-of-bounds reads and potential\nmemory corruption during later parameter handling (e.g. STATE_COOKIE\nprocessing and kmemdup() copies).\n\nAdd a bounds check in sctp_unpack_cookie() to ensure the cached INIT\nchunk length does not exceed the available data in the COOKIE_ECHO\nbuffer before it is used."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"cc272185c9a9a4b7febc2de52eeaa3d00f19091e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"edccbf3d63b0a3362bc916ea72edacc1e1ca456a","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0861615c28de668669d748ef4eb913ea9262d13b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/sm_make_chunk.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/sm_make_chunk.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/cc272185c9a9a4b7febc2de52eeaa3d00f19091e"},{"url":"https://git.kernel.org/stable/c/edccbf3d63b0a3362bc916ea72edacc1e1ca456a"},{"url":"https://git.kernel.org/stable/c/0861615c28de668669d748ef4eb913ea9262d13b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable COOKIE_ECHO processing is reached by remote SCTP packets delivered through the IPv4/IPv6 SCTP protocol handlers to a listening SCTP endpoint.\nAC:L - In a deployment with SCTP cookie HMAC disabled, the attacker can obtain a cookie through the normal INIT/INIT_ACK exchange, modify the cached INIT length, and send the forged COOKIE_ECHO without races or conditions outside attacker control.\nPR:N - The path is pre-authentication network protocol handling for a listening SCTP server; no local account or SCTP authentication is required when cookie HMAC is disabled.\nUI:N - Exploitation only requires sending SCTP handshake packets to the target listener and does not require victim user action.\nS:U - The impact is within the Linux kernel/network stack security authority and does not cross a separate boundary such as guest-to-host or IOMMU isolation.\nC:H - The inflated cached INIT length drives out-of-bounds parameter walking and attacker-sized kmemdup() reads beyond the received skb, which can expose kernel memory.\nI:H - The bug is kernel memory-safety corruption during nested parameter handling, and the higher-severity choice is appropriate because attacker-controlled parsing and copies beyond the valid buffer can corrupt kernel association state and plausibly support stronger primitives.\nA:H - The out-of-bounds reads and large attacker-controlled copies can trigger kernel faults, KASAN splats, allocation failure paths, or repeated remote crashes of SCTP processing."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:34:30.435Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53246","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:27:37.139455Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:57:31.408Z"}}]}}}