CVE-2026-80890
In the Linux kernel, the following vulnerability has been resolved: sctp: reject stale cookies with mismatched verification tags sctp_unpack_cookie() skips cookie expiration checks whenever an as…
Overview
CVE-2026-80890 is a known-severity vulnerability. It was published on September 4, 2026.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
sctp: reject stale cookies with mismatched verification tags
sctp_unpack_cookie() skips cookie expiration checks whenever an
association already exists. This is broader than the exception in
RFC 9260 Section 5.2.4.
For an existing association, Section 5.2.4 permits an expired State
Cookie only when both Verification Tags in the cookie match the current
association. Otherwise, the packet SHOULD be discarded and a Stale
Cookie ERROR MUST be sent.
The broad check lets an expired Action A restart cookie reach
sctp_sf_do_dupcook_a(). In a runtime test with the default 60 second
cookie lifetime, replaying such a cookie after 65 seconds returned a
COOKIE-ACK and restarted the association.
Check cookie expiration unless both Verification Tags match. This
preserves the Action D exception for a lost COOKIE ACK while rejecting
expired cookies in all other cases.
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
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Frequently asked questions
What is CVE-2026-80890?
CVE-2026-80890 is a known-severity vulnerability. It was published on September 4, 2026.
How severe is CVE-2026-80890?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2026-80890?
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.
How can CyberStrike help with CVE-2026-80890?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-80890 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.