CVE-2026-96940 Microsoft Exchange Server Elevation of Privilege Vulnerability
An authorized attacker can elevate privileges on Microsoft Exchange Server due to weak authentication mechanisms.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-96940?
CVE-2026-96940 is a high-severity vulnerability in Microsoft Exchange Server, published on 2 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Weakness: CWE-1390
Which versions are affected by CVE-2026-96940?
It affects 2 products.
Products include Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.
How do I fix CVE-2026-96940?
No fix has been published for CVE-2026-96940 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-96940 being exploited?
There is no known exploitation of CVE-2026-96940 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
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-q9jh-jffv-9xvh.