CVE-2026-26154 Windows Server Update Service (WSUS) Tampering Vulnerability
An unauthorized attacker can tamper with data in Windows Server Update Service over the network due to improper input validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-26154?
CVE-2026-26154 is a high-severity missing authorization vulnerability in Microsoft Windows Server 2012, published on 14 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper input validation in Windows Server Update Service allows an unauthorized attacker to perform tampering over a network.
Weakness: CWE-20
Which versions are affected by CVE-2026-26154?
It affects 6 products.
Products include Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025.
How do I fix CVE-2026-26154?
No fix has been published for CVE-2026-26154 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-26154 being exploited?
There is no known exploitation of CVE-2026-26154 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows Server 2012
- CVE-2025-59287 Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data
- CVE-2026-69595 Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability
- CVE-2026-78445 Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability
- CVE-2026-41089 Windows Netlogon Remote Code Execution Vulnerability
- CVE-2024-43639 Windows KDC Proxy Remote Code Execution Vulnerability
Sources
Also known as GHSA-xm9h-x34f-j9hj.