Sep 2026: Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2026-55007 Published on September 8, 2026
Microsoft Exchange Server Remote Code Execution Vulnerability
Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
Weakness Type
What is a Double-free Vulnerability?
The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. When a program calls free() twice with the same argument, the program's memory management data structures become corrupted. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack.
CVE-2026-55007 has been classified to as a Double-free vulnerability or weakness.
Products Associated with CVE-2026-55007
stack.watch emails you whenever new vulnerabilities are published in Microsoft Exchange Server 2019 or Microsoft Exchange Server Se. Just hit a watch button to start following.
Affected Versions
Microsoft Exchange Server 2019 Cumulative Update 14:- Version 15.02.0.0 and below 15.02.1544.046 is affected.
- Version 15.02.0.0 and below 15.02.1748.051 is affected.
- Version 15.02.0.0 and below 15.02.2562.049 is affected.