Vulnerability Description
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
CVSS Score
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Sharepoint Server | < 16.0.19725.20434 |
Related Weaknesses (CWE)
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040PatchVendor Advisory
- https://github.com/sfewer-r7/CVE-2026-55040Exploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-ExploitThird Party Advisory
- https://www.rapid7.com/blog/post/ra-microsoft-sharepoint-jwt-token-authenticatioUS Government Resource
FAQ
What is CVE-2026-55040?
CVE-2026-55040 is a vulnerability with a CVSS score of 9.1 (CRITICAL). Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
How severe is CVE-2026-55040?
CVE-2026-55040 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-55040?
Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Sharepoint Server.