BaseFortify

Publication date: 2025-12-16

Last updated on: 2025-12-18

Assigner: kernel.org

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. ]

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-12-16

Last Modified

2025-12-18

Generated

2026-07-06

AI Q&A

2025-12-16

EPSS Evaluated

2026-07-05

NVD

CVE-2025-68313

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability involves the RDSEED instruction on AMD Zen5 CPUs, where the 16-bit and 32-bit register output variants can return a random value of 0 at a rate inconsistent with expected randomness, while incorrectly signaling success. This means the CPU may provide non-random data as if it were valid random data.

Impact Analysis

The vulnerability can impact systems relying on RDSEED for random number generation by providing non-random values that appear valid. This can weaken cryptographic operations or any security mechanisms depending on high-quality randomness, potentially leading to security risks.

Mitigation Strategies

Apply the Linux kernel update that includes the fix for the RDSEED issue on AMD Zen5 CPUs, which adds microcode revision checks to address the problem.

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