---
id: CVE-2025-68313
title: |-
  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 inco…
summary: |-
  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 inco…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-338
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3e4147f33f8b647775357bae0248b9a2aeebfcd2 <
    e980de2ff109dacb6d9d3a77f01b27c467115ecb
  - >-
    Linux >= 3e4147f33f8b647775357bae0248b9a2aeebfcd2 <
    36ff93e66d0efc46e39fab536a9feec968daa766
  - >-
    Linux >= 3e4147f33f8b647775357bae0248b9a2aeebfcd2 <
    607b9fb2ce248cc5b633c5949e0153838992c152
  - Linux 5953e7a89966fc5a42124a08ba33a9c57ba5173c
  - Linux >= 6.6.156 < 6.7
  - Linux 6.8
published: '2025-12-16'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:19:11.873'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68313'
references:
  - url: 'https://git.kernel.org/stable/c/36ff93e66d0efc46e39fab536a9feec968daa766'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/607b9fb2ce248cc5b633c5949e0153838992c152'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e980de2ff109dacb6d9d3a77f01b27c467115ecb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-68313.json
  - url: 'https://access.redhat.com/security/cve/CVE-2025-68313'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2422831'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2025-68313'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68313'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2025121654-CVE-2025-68313-c65d@gregkh/T
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00139
epssPercentile: 0.03245
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T22:00:51.579306Z'
scores:
  nvd: 7.1
  vendor: 5.5
ingestedAt: '2026-09-02T13:44:41.298Z'
---

## Overview

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. ]

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-68313.json)