CVE-2026-46227

A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation. A race condition exists in the SCTP_SENDALL path where a cached list entry is not properly revalidated after the socket lock is temporarily released. This allows a local attacker or a remote attacker (via a network abort) to trigger a use-after-free or type confusion vulnerability. Successful exploitation can lead to a controlled indirect call, potentially resulting in arbitrary code execution.

A stale list cursor in the SCTP_SENDALL path can be used after sctp_sendmsg_to_asoc() temporarily drops the socket lock while waiting for send buffer space. During this window another local thread can peel off or close the cached next association, or the association can be removed by a network ABORT, leaving the iterator to advance to a freed or migrated object. This creates a use after free or type confusion in the SCTP association list walk and may allow kernel memory corruption. For the CVSS the PR:L is used because triggering requires a local unprivileged process with access to SCTP socket operations, not administrator rights. The issue is not a pure remote network bug because local code execution is needed to drive SCTP_SENDALL and related socket operations, although network ABORT traffic can participate in one removal path.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module sctp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.