CVE-2026-68376

/// Technical description

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

sctp: fix auth_hmacs array size in struct sctp_cookie

The auth_hmacs array in struct sctp_cookie is supposed to store a complete

SCTP_AUTH_HMAC_ALGO parameter, which consists of a struct sctp_paramhdr

followed by N HMAC identifiers.

However, the array size was calculated using an extra 2 bytes instead of

sizeof(struct sctp_paramhdr), which is 4 bytes. When four HMAC identifiers

are configured, the HMAC-ALGO parameter stored in the endpoint is larger

than the auth_hmacs buffer in the cookie.

As a result, sctp_association_init() copies beyond the end of auth_hmacs

when initializing the association, corrupting the adjacent auth_chunks

field. This can lead to an invalid HMAC identifier being accepted and later

cause an out-of-bounds read in sctp_auth_get_hmac().

Fix the array size calculation by including the full SCTP parameter header

size.

/// 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