CVE-2026-45501 Microsoft Exchange Server Spoofing Vulnerability
An authorized attacker can exploit a server-side request forgery flaw in Microsoft Exchange Server to perform spoofing attacks over the network.
- 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-2026-45501?
CVE-2026-45501 is a medium-severity server-side request forgery vulnerability in Microsoft Exchange Server, published on 9 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to perform spoofing over a network.
Which versions are affected by CVE-2026-45501?
It affects 2 products.
Products include Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.
How do I fix CVE-2026-45501?
No fix has been published for CVE-2026-45501 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-45501 being exploited?
There is no known exploitation of CVE-2026-45501 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-rc45-hpv2-j3hh.