CVE-2026-74688
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
In the Linux kernel, the SCTP protocol has a use-after-free vulnerability. sctp_make_heartbeat_ack() caches a pointer to the transport without taking a reference, and when the transport is removed, a queued control chunk may retain a dangling pointer, leading to memory corruption.
Risk Assessment
The risk involves potential exploitation of use-after-free to execute arbitrary code or crash the system, which could compromise system integrity.
Recommendation
It is recommended to update the Linux kernel to a version containing the fix that clears chunk->transport for queued control chunks when removing the transport.
Original NVD description (English source)
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.