CVE-2026-89479

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

sctp: stop processing a packet once its association is deleted

sctp_endpoint_bh_rcv() looks the association up only when chunk->asoc is

NULL, and caches the result in chunk->asoc and chunk->transport without

taking a reference.

A packet that matches no association is handed to the endpoint, so a peer

can bundle COOKIE ECHO, SHUTDOWN and SHUTDOWN ACK in one packet. The

COOKIE ECHO creates the association, the SHUTDOWN chunk caches it, and

with the outqueue empty the SHUTDOWN ACK reaches sctp_sf_do_9_2_final(),

so the association and its transports are freed.

The endpoint loop has no counterpart to the asoc->base.dead check in

sctp_assoc_bh_rcv(). The next chunk writes to last_time_heard in the freed

transport and is then passed to sctp_do_sm() with the freed association.

The transport is freed through RCU, so this needs the packet to come off

the socket backlog, where the loop runs in task context.

The endpoint loo

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References