CVE-2026-74688
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-74688.md and follow it. Check whether this project is affected by CVE-2026-74688. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/18d704bdd809377dfd81a3c2f42426763b5da227
- https://git.kernel.org/stable/c/4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7
- https://git.kernel.org/stable/c/6160e756db81d6cb63e3e2952efcf6c5134be385
- https://git.kernel.org/stable/c/8de65194a04d2552cd39b6c67d942d490f22d174
- https://git.kernel.org/stable/c/936658ec41c28c397ef390140e02d4c91ade92f0
- https://git.kernel.org/stable/c/c9158ceaf27780ef64534ad72f44ffde3f8ccc49
- https://git.kernel.org/stable/c/dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886
- https://git.kernel.org/stable/c/fad4766a74220fe579c6fcaa10ba01c23529814f