{"id":"CVE-2026-74752","title":"sctp: validate cookie AUTH state before use","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate cookie AUTH state before use\n\nWhen cookie authentication is disabled, COOKIE_ECHO restores fixed-size\nAUTH fields directly from peer-controlled cookie by…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-805"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 4a4410de8dc6903d859c9e1731fc6dcee28bd072","Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 7f17984cfa697613800eb693e183b06884129bd3","Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 88619b117be1daf633ce32210570ce35a0bd1c98","Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 3dbb44d88b1e94dd31fe43588af7437b34b44d56","Linux 2.6.24"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T19:16:25.350604Z"},"published":"2026-08-26","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:46:23.915Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74752","references":[{"url":"https://git.kernel.org/stable/c/4a4410de8dc6903d859c9e1731fc6dcee28bd072"},{"url":"https://git.kernel.org/stable/c/7f17984cfa697613800eb693e183b06884129bd3"},{"url":"https://git.kernel.org/stable/c/88619b117be1daf633ce32210570ce35a0bd1c98"},{"url":"https://git.kernel.org/stable/c/3dbb44d88b1e94dd31fe43588af7437b34b44d56"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74752.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74752"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2524422"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74752"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74752"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082600-CVE-2026-74752-6509@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:85321"},{"url":"https://access.redhat.com/errata/RHSA-2026:85773"},{"url":"https://access.redhat.com/errata/RHSA-2026:85774"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00524,"epssPercentile":0.44252,"patched":["10base_smtv","enterprise_linux_appstream_v_10","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_crb_v_8","enterprise_linux_hidden_v_10","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_nfv_v_8","enterprise_linux_real_time_v_10","enterprise_linux_rt_v_8"],"scores":{"cna":9.8,"vendor":8.8},"ingestedAt":"2026-10-16T19:46:24.322Z","slug":"CVE-2026-74752","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsctp: validate cookie AUTH state before use\n\nWhen cookie authentication is disabled, COOKIE_ECHO restores fixed-size\nAUTH fields directly from peer-controlled cookie bytes.  A forged RANDOM\nlength, HMAC list, or CHUNKS list can then reach association consumers\nwith lengths or identifiers that were never validated against the local\nbacking arrays.\n\nA forged RANDOM length can cause out-of-bounds reads during key-vector\nconstruction.  A forged HMAC identifier also caused a 32-byte write past\na zero-length AUTH chunk, providing a primitive for a local privilege\nescalation chain.\n\nValidate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie\ntrust boundary before copying them into the association.  Reject invalid\ntypes, malformed lengths, unsupported HMAC identifiers, HMAC lists\nwithout SHA1, and forbidden chunk ids.\n\n## Affected\n\n- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 4a4410de8dc6903d859c9e1731fc6dcee28bd072`\n- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 7f17984cfa697613800eb693e183b06884129bd3`\n- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 88619b117be1daf633ce32210570ce35a0bd1c98`\n- `Linux >= 1f485649f52929d9937b346a920a522a7363e202 < 3dbb44d88b1e94dd31fe43588af7437b34b44d56`\n- `Linux 2.6.24`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:85321** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85321)\n- **RHSA-2026:85773** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:85773)\n- **RHSA-2026:85774** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:85774)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74752.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":227185,"id":"CVE-2026-74752","ts":1792586940883,"field":"cvss","old":"8.8","new":"9.8"},{"seq":227184,"id":"CVE-2026-74752","ts":1792586940883,"field":"severity","old":"high","new":"critical"},{"seq":225737,"id":"CVE-2026-74752","ts":1792498403126,"field":"cvss","old":"9.8","new":"8.8"},{"seq":225736,"id":"CVE-2026-74752","ts":1792498403126,"field":"severity","old":"critical","new":"high"}]}