Inefficient Algorithmic Complexity in Microsoft Exchange Server Subscription Edition RTM - CVE-2026-118153
Published: November 11, 2026
Vulnerability identifier: #VU165052
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-118153
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in Microsoft Exchange Server when processing network input. A remote attacker can send specially crafted network input to trigger excessive computational resource consumption and cause a denial of service.
Affected software
Microsoft Exchange Server Subscription Edition RTM
How to mitigate CVE-2026-118153
Install security update from vendor's website.
Microsoft Exchange Server Subscription Edition RTM - update to 15.02.2562.057