CVE-2026-74688
In the Linux kernel, the following vulnerability has been resolved: sctp: clear control chunk transport if it is being removed sctp_make_heartbeat_ack() caches the destination transport in chunk->transport without taking a reference. When src_out_of_asoc_ok is enabled, the HEARTBEAT ACK may remain queued on control_chunk_list instead of being transmitted immediately. If the peer transport is removed while the chunk is still queued, sctp_assoc_rm_peer() drops the transport and schedules it for RCU freeing, but only clears cached transport pointers in out_chunk_list. The queued control chunk therefore retains a dangling transport pointer. Once an ASCONF_ACK clears the suppression and the queued control chunk is transmitted, SCTP dereferences the stale transport pointer, leading to a use-after-free. Fix this by also clearing chunk->transport for queued control chunks in control_chunk_list when removing the transport.
Affected versions
Linux kernel versions
3.1
and later are affected. Fixed in
5.10.265,
5.15.216,
6.1.183,
6.6.152,
6.12.104,
6.18.45,
7.1.9,
7.2
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-74688?
CVE-2026-74688 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 3.1 onward and has been patched in 5.10.265, 5.15.216, 6.1.183 and others. CVE-2026-74688 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-74688?
Yes. CVE-2026-74688 has been patched. Fixed versions include 5.10.265, 5.15.216, 6.1.183 and others. If you are running Linux kernel 3.1 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-74688 actively exploited?
No. CVE-2026-74688 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.