CVE-2026-72398

Technical Description

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

sctp: add INIT verification after cookie unpacking

In SCTP handshake, the INIT chunk is initially processed by the server

and embedded into the cookie carried in INIT-ACK. The client then

returns this cookie via COOKIE-ECHO, where the server unpacks it and

reconstructs the original INIT chunk.

When cookie authentication is enabled, the cookie contents are protected

against tampering, so reusing the unpacked INIT without re-verification

is safe.

However, when cookie authentication is disabled, the reconstructed INIT

can no longer be trusted. In this case, the INIT must be explicitly

validated after unpacking to avoid processing potentially tampered data.

Add sctp_verify_init() checks after cookie unpacking in COOKIE-ECHO

processing paths (sctp_sf_do_5_1D_ce() and sctp_sf_do_5_2_4_dupcook())

when cookie_auth_enable is disabled. On failure, the new association is

freed and the packet is discarded.

Also tighten cooki

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