CVE-2026-74587sctp: fix use-after-free of cached ASCONF chunk
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: sctp: fix use-after-free of cached ASCONF chunk addip_last_asconf caches the outstanding outbound ASCONF chunk. The normal ASCONF-ACK completion path releases the chunk and clears the pointer. However, sctp_asconf_queue_teardown() releases the cached chunk without clearing addip_last_asconf. During peer restart handling, sctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes sctp_asconf_queue_teardown() while the association remains alive and leaves the pointer dangling. A delayed authenticated ASCONF-ACK can then reach sctp_sf_do_asconf_ack(), which accesses the stale chunk and passes it to sctp_process_asconf_ack(), causing a use-after-free and a second release. Clearing the pointer exposes a race with T4 expiry. Peer restart handling queues the timer stop before the purge, but SCTP_CMD_TIMER_STOP uses timer_delete(), which does not wait for a callback already running on another CPU. Such a callback can reach sctp_sf_t4_timer_expire() after the purge and dereference NULL. Clear addip_last_asconf after releasing the cached chunk, and make sctp_sf_t4_timer_expire() consume a stale T4 expiry if no outstanding ASCONF remains.
- CVSS
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from a000c01e60e40e15304ffe48fff051d17a7bea91 before 10459b03e2d9ee12435e96f587de4d4cacdbf435; from a000c01e60e40e15304ffe48fff051d17a7bea91 before e1bb114e09372fd6e03387ced9ef566da336ed6c; from a000c01e60e40e15304ffe48fff051d17a7bea91 before 179676f0166230c80053a392303485b37c93dd33; from a000c01e60e40e15304ffe48fff051d17a7bea91 before dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d; from a000c01e60e40e15304ffe48fff051d17a7bea91 before 618b5c6d049896fcfabb91afc072954c92cb2693; from a000c01e60e40e15304ffe48fff051d17a7bea91 before 07daf4f9750104960a1d60831b2353c0d41f35fb; from a000c01e60e40e15304ffe48fff051d17a7bea91 before d949992bc3f00027a2c755e860a11950c75f6073; from a000c01e60e40e15304ffe48fff051d17a7bea91 before 8c283e7b56adce00193837f3311b06662466fb21 | CNA record |
References
- https://git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435
- https://git.kernel.org/stable/c/e1bb114e09372fd6e03387ced9ef566da336ed6c
- https://git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33
- https://git.kernel.org/stable/c/dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d
- https://git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693
- https://git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb
- https://git.kernel.org/stable/c/d949992bc3f00027a2c755e860a11950c75f6073
- https://git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.