#VU102763 Type Confusion in Windows Server - CVE-2025-21326

Vulnerability identifier: #VU102763

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-21326

CWE-ID: CWE-843

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a type confusion error in Internet Explorer. A remote attacker can trick a victim to open a specially crafted file, trigger a type confusion error and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows Server: before 2016, 2022 23H2, 2025, 2016, 2016, 2016

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21326

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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.