Information disclosure in Microsoft Windows Themes

1) Information disclosure

EUVDB-ID: #VU102803

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-21308

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in Windows Themes. A remote attacker can trick a victim to load a malicious file onto a vulnerable system and gain unauthorized access to sensitive information on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows: before 10 21H2 10.0.19044.5371, 10 22H2 10.0.19045.5371, 10 1507 10.0.10240.20890, 10 1607 10.0.14393.7699, 10 1809 10.0.17763.6775, 11 22H2 10.0.22621.4751, 11 23H2 10.0.22631.4751, 11 24H2 10.0.26100.2894, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371, 10 21H2 10.0.19044.5371

Windows Server: before 2012 R2 6.3.9600.22371, 2012 6.2.9200.25273, 2016 10.0.14393.7699, 2022 10.0.20348.3091, 2025 10.0.26100.2894, 2012 R2 6.3.9600.22371, 2012 R2 6.3.9600.22371, 2012 R2 6.3.9600.22371

CPE2.3

• cpe:2.3:o:microsoft:windows:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:*:*:*:*:*:*:*:*

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21308

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.