9.8

CVE-2025-21311: Windows NTLM V1 Elevation of Privilege Vulnerability

Analyzed
AliasesUBUNTU-CVE-2025-21311DEBIAN-CVE-2025-21311
Published 14-01-2025Last modified 09-06-2026

Vulnerability summary

CVE-2025-21311 is a critical (CVSS 9.8) vulnerability in microsoft windows_11_24h2. EPSS estimates a 2.26% chance of exploitation in the next 30 days, higher than 82.8% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
2.26%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 14-01-2025
    PublishedVulnerability first disclosed.
  2. 09-06-2026
    Last modifiedVulnerability information updated.

Description

Windows NTLM V1 Elevation of Privilege Vulnerability

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

2.26%

Chance of exploitation in the next 30 days

Percentile

83%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 2.23% on 22-09-2026

22-09-202622-10-2026

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

Microsoft6 products
Ubuntu2 products
  • squidAll versions (No fix recorded)
  • squid3All versions (No fix recorded)
Debian1 product
  • squidAll versions (No fix recorded) | < 7.1-1

3 vendors · 9 products

References

4 links