Acceptance of Extraneous Untrusted Data With Trusted Data in Microsoft Windows and Windows Server - CVE-2025-29842

Vulnerability identifier: #VU109103

CSH Severity: High

CVSS v4: 7.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-29842

CWE-ID: CWE-349

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to improper input validation in UrlMon. A remote attacker can trick a victim to open a specially crafted file and bypass a security feature.

Microsoft Windows
Windows Server

Install updates from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.5854, 10 22H2 10.0.19045.5854, 10 1507 10.0.10240.21014, 10 1607 10.0.14393.8066, 10 1809 10.0.17763.7314, 11 22H2 10.0.22621.5335, 11 23H2 10.0.22631.5335, 11 24H2 10.0.26100.3981, 11 24H2 10.0.26100.4061
Windows Server - addressed in versions 2012 R2 6.3.9600.22577, 2016 10.0.14393.8066, 2019 10.0.17763.7314, 2022 23H2 10.0.25398.1611, 2022 10.0.20348.3630, 2022 10.0.20348.3692, 2025 10.0.26100.3981, 2025 10.0.26100.4061

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-29842

• Security Feature Bypass in Microsoft UrlMon