CVE-2026-72940 Windows Schannel Remote Code Execution Vulnerability
Heap-based buffer overflow in Windows Schannel allows remote attackers to execute arbitrary code over the network.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-72940?
CVE-2026-72940 is a high-severity memory corruption vulnerability in Microsoft Windows 11 23h2, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Heap-based buffer overflow in Windows Schannel allows an unauthorized attacker to execute code over a network.
Weakness: CWE-122
Which versions are affected by CVE-2026-72940?
It affects 6 products.
Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows Server 2022, Microsoft Windows Server 2025.
How do I fix CVE-2026-72940?
No fix has been published for CVE-2026-72940 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72940 being exploited?
There is no known exploitation of CVE-2026-72940 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 11 23h2
- CVE-2026-81963 Microsoft Windows Link Following
- CVE-2026-100219 Microsoft QUIC Remote Code Execution Vulnerability
- CVE-2026-96909 Windows BitLocker Remote Code Execution Vulnerability
- CVE-2026-62815 Microsoft QUIC Remote Code Execution Vulnerability
- CVE-2026-45657 Windows Kernel Remote Code Execution Vulnerability
Sources
Also known as GHSA-763c-9mqj-7c38.