CVE-2026-70571 Microsoft Exchange Server Remote Code Execution Vulnerability
An unauthorized attacker can execute arbitrary code remotely via a stack-based buffer overflow in Microsoft Exchange Server.
- 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-2026-70571?
CVE-2026-70571 is a high-severity memory corruption vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
Weakness: CWE-121
Which versions are affected by CVE-2026-70571?
How do I fix CVE-2026-70571?
No fix has been published for CVE-2026-70571 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-2026-70571 being exploited?
There is no known exploitation of CVE-2026-70571 in the wild and no public exploit code.
Sources
Also known as GHSA-6m32-fvj6-jjf4.