PT-2026-2701 · Microsoft · Windows Server Update Services+1

Chris Ward · Published 2026-01-13 · Updated 2026-02-17 · CVE-2026-20856

Positive Technologies (AI Summary)

CVSS v3.1

8.1

High

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Windows Server Update Service (affected versions not specified)

Description A flaw in input validation within Windows Server Update Service could allow a remote attacker to execute code on the network. This could lead to arbitrary code execution and system compromise.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Weakness Enumeration

CWE-20

Related Identifiers

BDU:2026-00439

CVE-2026-20856

Affected Products

Windows

Windows Server Update Services

References · 8

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-20856 · Security Note
• https://osv.dev/vulnerability/CVE-2026-20856 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-00439 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20856 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-20856 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-20856 · Vendor Advisory
• https://twitter.com/ThreatSynop/status/2011355945075388698 · Twitter Post
• https://twitter.com/CVEnew/status/2011759670025662904 · Twitter Post