CVE-2026-74587
sctp: fix use-after-free of cached ASCONF chunk
Description
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.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Clear pointer after releasing cached chunk.
- Handle stale timer expiry if no ASCONF remains.
- Update the Linux kernel.
References to Advisories, Solutions, and Tools
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CVE-2026-74587.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74587 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74587
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-74587 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74587 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': '10459b03e2d9ee12435e96f587de4d4cacdbf435', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': 'e1bb114e09372fd6e03387ced9ef566da336ed6c', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': '179676f0166230c80053a392303485b37c93dd33', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': 'dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': '618b5c6d049896fcfabb91afc072954c92cb2693', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': '07daf4f9750104960a1d60831b2353c0d41f35fb', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': 'd949992bc3f00027a2c755e860a11950c75f6073', 'versionType': 'git'}, {'status': 'affected', 'version': 'a000c01e60e40e15304ffe48fff051d17a7bea91', 'lessThan': '8c283e7b56adce00193837f3311b06662466fb21', 'versionType': 'git'}], 'programFiles': ['net/sctp/associola.c', 'net/sctp/sm_statefuns.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.265', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.216', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.183', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/sctp/associola.c', 'net/sctp/sm_statefuns.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb Added Reference https://git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435 Added Reference https://git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33 Added Reference https://git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693 Added Reference https://git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21 Added Reference https://git.kernel.org/stable/c/d949992bc3f00027a2c755e860a11950c75f6073 Added Reference https://git.kernel.org/stable/c/dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d Added Reference https://git.kernel.org/stable/c/e1bb114e09372fd6e03387ced9ef566da336ed6c