CVE-2026-83856 Windows Event Logging Service Remote Code Execution Vulnerability
An out-of-bounds read in the Windows Event Logging Service allows remote attackers to execute arbitrary code without authentication.
- 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-2026-83856?
CVE-2026-83856 is a high-severity memory corruption vulnerability in Microsoft Windows 11 23h2, published on 13 Oct 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
Out-of-bounds read in Windows Event Logging Service allows an unauthorized attacker to execute code over a network.
Weakness: CWE-125
Which versions are affected by CVE-2026-83856?
It affects 7 products.
Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2022 and 1 more.
How do I fix CVE-2026-83856?
No fix has been published for CVE-2026-83856 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-2026-83856 being exploited?
There is no known exploitation of CVE-2026-83856 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-fw5f-5j4p-c43m.