{"cve":"CVE-2026-74587","nvd":{"published":"2026-08-22T16:16:30.830","modified":"2026-10-16T20:17:41.753","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix use-after-free of cached ASCONF chunk\n\naddip_last_asconf caches the outstanding outbound ASCONF chunk. The normal\nASCONF-ACK completion path releases the chunk and clears the pointer.\n\nHowever, sctp_asconf_queue_teardown() releases the cached chunk without\nclearing addip_last_asconf. During peer restart handling,\nsctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes\nsctp_asconf_queue_teardown() while the association remains alive and leaves\nthe pointer dangling.\n\nA delayed authenticated ASCONF-ACK can then reach sctp_sf_do_asconf_ack(),\nwhich accesses the stale chunk and passes it to sctp_process_asconf_ack(),\ncausing a use-after-free and a second release.\n\nClearing the pointer exposes a race with T4 expiry. Peer restart handling\nqueues the timer stop before the purge, but SCTP_CMD_TIMER_STOP uses\ntimer_delete(), which does not wait for a callback already running on\nanother CPU. Such a callback can reach sctp_sf_t4_timer_expire() after\nthe purge and dereference NULL.\n\nClear addip_last_asconf after releasing the cached chunk, and make\nsctp_sf_t4_timer_expire() consume a stale T4 expiry if no outstanding\nASCONF remains.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":[],"references":["https://git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb","https://git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435","https://git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33","https://git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693","https://git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-74587","score":0.005,"percentile":0.42525,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}