CVE-2026-55040Critical· 9.1▾ Hadal⚠ Exploited in the wildPoC availableWeak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
▾ Hadal zone — Critical and actively exploited (CISA KEV / 0day)
impact 50.1 · likelihood 10.1 · exploitation 25
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 2 sources. Availability, not in-the-wild use.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Exploit-prediction probability, daily snapshots since Sep 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CVEORG
Federal remediation due Aug 21, 2026
40%
40% → 51%
Last analysed / modified upstream
5 GitHub repos · Nuclei ×1 (last check)
Added to the CISA catalog on Aug 18, 2026. Federal remediation due Aug 21, 2026. View catalog ↗
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
sharepoint_enterprise_server_2016 >= 16.0.0 < 16.0.5561.1001sharepoint_server_2019 >= 16.0.0 < 16.0.10417.20175sharepoint_server_subscription_edition >= 16.0.0 < 16.0.19725.20434Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-56164Medium· 5.3Microsoft SharePoint Server Elevation of Privilege Vulnerability
CVE-2026-50522Critical· 9.8Microsoft SharePoint Remote Code Execution Vulnerability
CVE-2026-85880High· 7.8Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.
CVE-2026-81963High· 7.8Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
CVE-2026-63520High· 8.1Microsoft SharePoint Server Remote Code Execution Vulnerability
CVE-2026-70324High· 8.8Microsoft SharePoint Elevation of Privilege Vulnerability