CVE-2026-21530 Windows Rich Text Edit Elevation of Privilege Vulnerability
A double free vulnerability in Windows Rich Text Edit allows an authorized local attacker to elevate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-21530?
CVE-2026-21530 is a medium-severity use after free vulnerability in Microsoft Windows 10 1607, published on 12 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Double free in Windows Rich Text Edit allows an authorized attacker to elevate privileges locally.
Weakness: CWE-415
Which versions are affected by CVE-2026-21530?
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-2026-21530?
No fix has been published for CVE-2026-21530 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-21530 being exploited?
There is no known exploitation of CVE-2026-21530 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-xp4f-mw6j-jxm8.