{"id":"CVE-2026-64551","title":"sctp: validate STALE_COOKIE cause length before reading staleness","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate STALE_COOKIE cause length before reading staleness\n\nWhen an ERROR chunk with a STALE_COOKIE cause is received in the\nCOOKIE_ECHOED state, sctp_sf_do_5_2_…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6022da37786701df1fc5dd946a6dcba59d5473b1","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 861f884f5471632c731cbbd612a1c072e391a624","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 588706ebaf8cdb4a4161602949eba365514b1db1","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a257b41ddfe9e327b26581ad2777f04b23ac73f5","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 08a8f2d13f703924316e9aeac863a88ef50990c7","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ebe0a55d954fa8da383b6192edb8f763dcb002d5","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1cd23ca80784223fa2204e16203f754da4e821f8","Linux 2.6.12"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:42:25.961430Z"},"published":"2026-07-27","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:52:52.000Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64551","references":[{"url":"https://git.kernel.org/stable/c/6022da37786701df1fc5dd946a6dcba59d5473b1"},{"url":"https://git.kernel.org/stable/c/861f884f5471632c731cbbd612a1c072e391a624"},{"url":"https://git.kernel.org/stable/c/588706ebaf8cdb4a4161602949eba365514b1db1"},{"url":"https://git.kernel.org/stable/c/a257b41ddfe9e327b26581ad2777f04b23ac73f5"},{"url":"https://git.kernel.org/stable/c/08a8f2d13f703924316e9aeac863a88ef50990c7"},{"url":"https://git.kernel.org/stable/c/ebe0a55d954fa8da383b6192edb8f763dcb002d5"},{"url":"https://git.kernel.org/stable/c/bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0"},{"url":"https://git.kernel.org/stable/c/1cd23ca80784223fa2204e16203f754da4e821f8"}],"tags":["cve.org"],"epss":0.00514,"epssPercentile":0.42495,"ingestedAt":"2026-10-16T17:24:46.833Z","slug":"CVE-2026-64551","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate STALE_COOKIE cause length before reading staleness\n\nWhen an ERROR chunk with a STALE_COOKIE cause is received in the\nCOOKIE_ECHOED state, sctp_sf_do_5_2_6_stale() reads the 4-byte Measure\nof Staleness that follows the cause header:\n\n\terr   = (struct sctp_errhdr *)(chunk->skb->data);\n\tstale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err)));\n\nerr is the first cause in the chunk, not the STALE_COOKIE cause that\ncaused the dispatch, and nothing guarantees the staleness field is\npresent. sctp_walk_errors() only requires a cause to be as long as the\n4-byte header, so for a STALE_COOKIE cause of length 4 the read runs\npast the cause, and for a minimal ERROR chunk past skb->tail. The value\nis echoed to the peer in the Cookie Preservative of the reply INIT,\nleaking uninitialized memory.\n\nsctp_sf_cookie_echoed_err() already walks to the STALE_COOKIE cause, so\ncheck its length there and pass it to sctp_sf_do_5_2_6_stale(), which\nreads that cause instead of the first one. A STALE_COOKIE cause too\nshort to hold the staleness field is discarded.\n\nThe read is reachable by any peer that can drive an association into\nCOOKIE_ECHOED, including an unprivileged process using a raw SCTP socket\nin a user and network namespace.\n\n## Affected\n\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6022da37786701df1fc5dd946a6dcba59d5473b1`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 861f884f5471632c731cbbd612a1c072e391a624`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 588706ebaf8cdb4a4161602949eba365514b1db1`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a257b41ddfe9e327b26581ad2777f04b23ac73f5`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 08a8f2d13f703924316e9aeac863a88ef50990c7`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ebe0a55d954fa8da383b6192edb8f763dcb002d5`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1cd23ca80784223fa2204e16203f754da4e821f8`\n- `Linux 2.6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}