CVE-2025-68313 x86/CPU/AMD: Add RDSEED fix for Zen5
AMD Zen5 CPUs may return zero from RDSEED instructions, compromising random number generation quality for security-sensitive operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68313?
CVE-2025-68313 is a high-severity vulnerability in Linux, published on 16 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
x86/CPU/AMD: Add RDSEED fix for Zen5
There's an issue with RDSEED's 16-bit and 32-bit register output variants on Zen5 which return a random value of 0 "at a rate inconsistent with randomness while incorrectly signaling success (CF=1)". Search the web for AMD-SB-7055 for more detail.
Add a fix glue which checks microcode revisions.
[ bp: Add microcode revisions checking, rewrite. ]
Which versions are affected by CVE-2025-68313?
How do I fix CVE-2025-68313?
Apply the vendor's patch.
Is CVE-2025-68313 being exploited?
There is no known exploitation of CVE-2025-68313 in the wild and no public exploit code.
Sources
Also known as AZL-72628, BELL-CVE-2025-68313, DEBIAN-CVE-2025-68313, GHSA-hccf-2qv6-3rfj, ROOT-OS-DEBIAN-13-CVE-2025-68313, ROOT-OS-UBUNTU-2204-CVE-2025-68313 and 2 more.