{"id":"CVE-2026-55040","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-55040","summary":"Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.","details":"Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.","published":"2026-07-14T18:18:15.413","modified":"2026-08-19T04:17:23.540","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":{"score":0.05578,"percentile":0.92293,"asOf":"2026-08-26"},"cisaKev":{"dateAdded":"2026-08-18","dueDate":"2026-08-21","knownRansomwareCampaignUse":false},"exploitsKnown":2,"affectedPackages":[],"fix":null,"references":[{"type":"FIX","url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040"},{"type":"EXPLOIT","url":"https://github.com/sfewer-r7/CVE-2026-55040"},{"type":"EXPLOIT","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55040"},{"type":"WEB","url":"https://www.rapid7.com/blog/post/ra-microsoft-sharepoint-jwt-token-authentication-bypass-cve-2026-55040/"}],"provenance":{"sources":["OSV.dev","NVD","CISA KEV","FIRST.org (EPSS)"],"lastVerified":"2026-08-19T04:17:23.540"}}