CVE-2026-63516 Microsoft SharePoint Server Spoofing Vulnerability
An authorized attacker can exploit untrusted data deserialization in SharePoint 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-2026-63516?
CVE-2026-63516 is a medium-severity unsafe deserialization vulnerability in Microsoft Sharepoint Server, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.
Weakness: CWE-502
Which versions are affected by CVE-2026-63516?
It affects 1 product.
Products include Microsoft Sharepoint Server.
How do I fix CVE-2026-63516?
No fix has been published for CVE-2026-63516 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-63516 being exploited?
There is no known exploitation of CVE-2026-63516 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Sharepoint Server
- CVE-2026-50522 Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
- CVE-2026-58644 Microsoft SharePoint Deserialization of Untrusted Data
- CVE-2026-20963 Microsoft SharePoint Deserialization of Untrusted Data
- CVE-2025-53770 Microsoft SharePoint Deserialization of Untrusted Data
- CVE-2023-29357 Microsoft SharePoint Server Privilege Escalation
Sources
Also known as GHSA-jg9v-rf24-xph9.