CVE-2026-20849 Windows Kerberos Elevation of Privilege Vulnerability
An authorized attacker can elevate privileges over the network by exploiting untrusted inputs in Windows Kerberos security decisions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20849?
CVE-2026-20849 is a high-severity vulnerability in Microsoft Windows 10 1607, published on 13 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Reliance on untrusted inputs in a security decision in Windows Kerberos allows an authorized attacker to elevate privileges over a network.
Weakness: CWE-807
Which versions are affected by CVE-2026-20849?
It affects 14 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 8 more.
How do I fix CVE-2026-20849?
No fix has been published for CVE-2026-20849 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-20849 being exploited?
There is no known exploitation of CVE-2026-20849 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-j88c-7m8j-3g32.