4.6

CVE-2025-29943: amd64-microcode Write-what-where Condition

Deferred
AliasesUBUNTU-CVE-2025-29943DEBIAN-CVE-2025-29943
Published 16-01-2026Last modified 16-01-2026

Vulnerability summary

CVE-2025-29943 is a medium (CVSS 4.6) Write-what-where Condition vulnerability in amd64-microcode. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4.6, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.6/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.23%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:11242-1

Timeline

  1. 16-01-2026
    PublishedVulnerability first disclosed.
  2. 16-01-2026
    Last modifiedVulnerability information updated.

Description

Write what were condition within AMD CPUs may allow an admin-privileged attacker to modify the configuration of the CPU pipeline potentially resulting in the corruption of the stack pointer inside an SEV-SNP guest.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.23% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, administrative account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Debian1 product
  • amd64-microcodeAll versions (No fix recorded) | < 3.20251202.1
Ubuntu1 product
  • amd64-microcodeAll versions (No fix recorded) | < 3.20251202.1ubuntu0.24.04.1 | < 3.20251202.1ubuntu0.25.10.1 | < 3.20251202.1ubuntu1

2 vendors · 2 products

References

4 links