CVE-2026-55040
Microsoft SharePoint Weak Authentication Vulnerability
9.1
CVSS 3.1
17.5 %
EPSS (current)
2026-08-18
KEV addition
No
Ransomware
Timeline
Publication, first public exploit and KEV addition on a day axis.
Key facts
Vendor / product: Microsoft / SharePoint
Published: 2026-07-14 · Due (CISA): 2026-08-21
CWE: CWE-1390 · EU list: no
Exploit references (metadata only)
| Source | Reference | Title | Date |
|---|---|---|---|
| nuclei | javascript/cves/2026/CVE-2026-55040.yaml | Microsoft SharePoint Server - JWT Authentication Bypass | – |
References only — no downloads or instructions.