CVE-2025-40204
Published Nov 12, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.
Is your site exposed to CVE-2025-40204?
Run a free security scan — no signup, results in seconds.
References
Other References
https://git.kernel.org/stable/c/0b32ff285ff6f6f1ac1d9495787ccce8837d6405
https://git.kernel.org/stable/c/0e8b8c326c2a6de4d837b1bb034ea704f4690d77
https://git.kernel.org/stable/c/1cd60e0d0fb8f0e62ec4499138afce6342dc9d4c
https://git.kernel.org/stable/c/8019b3699289fce3f10b63f98601db97b8d105b0
https://git.kernel.org/stable/c/9c05d44ec24126fc283835b68f82dba3ae985209
https://git.kernel.org/stable/c/b93fa8dc521d00d2d44bf034fb90e0d79b036617
https://git.kernel.org/stable/c/dd91c79e4f58fbe2898dac84858033700e0e99fb
https://git.kernel.org/stable/c/ed3044b9c810c5c24eb2830053fbfe5fd134c5d4
Frequently Asked Questions
What is CVE-2025-40204? +
In the Linux kernel, the following vulnerability has been resolved:
sctp: Fix MAC comparison to be constant-time
To prevent timing attacks, MACs need to be compared in constant time.
Use the appropriate helper function for this.
How do I check if I'm vulnerable to CVE-2025-40204? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.