CVE-2026-45583 Microsoft Exchange Server Remote Code Execution Vulnerability
An unauthorized attacker can execute arbitrary code over the network on Microsoft Exchange Server due to improper code generation control.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-45583?
CVE-2026-45583 is a high-severity code injection vulnerability in Microsoft Exchange Server, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Improper control of generation of code ('code injection') in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
Weakness: CWE-94
Which versions are affected by CVE-2026-45583?
It affects 2 products.
Products include Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.
How do I fix CVE-2026-45583?
No fix has been published for CVE-2026-45583 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-45583 being exploited?
There is no known exploitation of CVE-2026-45583 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-2qq9-7ppw-4m9q.