CVE-2026-20856
CVSS v3
8.1
HIGH
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
Technical details
- Published
- 2026-01-13
- Last Modified
- 2026-01-15
Frequently asked questions
What is CVE-2026-20856?
Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
Is CVE-2026-20856 actively exploited?
Active exploitation of CVE-2026-20856 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2026-20856?
CVE-2026-20856 has a CVSS v3 base score of 8.1 (HIGH severity).
Is CVE-2026-20856 affecting your environment?
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