Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
Critical CVSS 9.1 Listed in CISA KEV
Summary
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
In-depth triage
No in-depth report has been generated yet (DR-003 v2 AI pipeline is under construction).
Affected products
- :
- Microsoft:SharePoint
Sources
- NVD DATABASE
- CISA KEV DATABASE
Original Links
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040 Patch
- https://github.com/sfewer-r7/CVE-2026-55040
- https://www.rapid7.com/blog/post/ra-microsoft-sharepoint-jwt-token-authentication-bypass-cve-2026-55040/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55040
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk reference
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk reference
- https://nvd.nist.gov/vuln/detail/CVE-2026-55040 reference
Timeline
- nvd_ingest NVD
- kev_ingest CISA KEV