7.8

CVE-2021-26889: Windows Update Stack Elevation of Privilege Vulnerability

Modified
Published 11-03-2021Last modified 19-08-2026

Vulnerability summary

CVE-2021-26889 is a high (CVSS 7.8) Link Following vulnerability in microsoft windows_10. EPSS estimates a 1.17% chance of exploitation in the next 30 days, higher than 67.1% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
1.17%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 11-03-2021
    PublishedVulnerability first disclosed.
  2. 19-08-2026
    Last modifiedVulnerability information updated.

Description

Windows Update Stack Elevation of Privilege Vulnerability

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.17%

Chance of exploitation in the next 30 days

Percentile

67%

Versus all other CVEs

30-day change

Increase +0.08 pp

From 1.08% 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

Microsoft12 products

1 vendor · 12 products

References

3 links