CVE-2026-55007 Microsoft Exchange Server Remote Code Execution Vulnerability
An unauthorized attacker can execute arbitrary code over the network due to a double free vulnerability 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-2026-55007?
CVE-2026-55007 is a high-severity memory corruption vulnerability in Microsoft Exchange Server, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
Weakness: CWE-415
Which versions are affected by CVE-2026-55007?
It affects 2 products.
Products include Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.
How do I fix CVE-2026-55007?
No fix has been published for CVE-2026-55007 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-2026-55007 being exploited?
There is no known exploitation of CVE-2026-55007 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Exchange Server
- CVE-2024-21410 Microsoft Exchange Server Privilege Escalation
- CVE-2021-34473 Microsoft Exchange Server Remote Code Execution
- CVE-2021-26855 Microsoft Exchange Server Remote Code Execution
- CVE-2021-34523 Microsoft Exchange Server Privilege Escalation
- CVE-2023-21529 Microsoft Exchange Server Deserialization of Untrusted Data
Sources
Also known as GHSA-phwr-836j-jgp8.