CVE-2026-74752 sctp: validate cookie AUTH state before use
A memory corruption vulnerability in the Linux kernel SCTP implementation allows local attackers to escalate privileges via forged cookie authentication data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74752?
CVE-2026-74752 is a critical memory corruption vulnerability in Linux, published on 26 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
sctp: validate cookie AUTH state before use
When cookie authentication is disabled, COOKIE_ECHO restores fixed-size AUTH fields directly from peer-controlled cookie bytes. A forged RANDOM length, HMAC list, or CHUNKS list can then reach association consumers with lengths or identifiers that were never validated against the local backing arrays.
A forged RANDOM length can cause out-of-bounds reads during key-vector construction. A forged HMAC identifier also caused a 32-byte write past a zero-length AUTH chunk, providing a primitive for a local privilege escalation chain.
Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie trust boundary before copying them into the association. Reject invalid types, malformed lengths, unsupported HMAC identifiers, HMAC lists without SHA1, and forbidden chunk ids.
Which versions are affected by CVE-2026-74752?
How do I fix CVE-2026-74752?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74752 being exploited?
There is no known exploitation of CVE-2026-74752 in the wild and no public exploit code.
Sources
Also known as AZL-97761, BELL-CVE-2026-74752, DEBIAN-CVE-2026-74752, GHSA-3494-mfxc-798j, UBUNTU-CVE-2026-74752.