CVE-2026-40365
Published: 12 May 2026
Summary
CVE-2026-40365 is a high-severity Insufficient Granularity of Access Control (CWE-1220) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 42.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-29647
Vulnerability details
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct RCE via insufficient access controls in network-accessible SharePoint maps to public-facing app exploitation and priv-esc.
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Use of granular security and privacy attributes enables finer access control than coarse permission models alone.
Documenting interface characteristics enables more granular control over internal access.
Requires the architecture to describe granularity and placement of controls, preventing insufficiently fine-grained access decisions.
Provides the necessary granularity by placing system management functions outside the reach of user-level access controls.
Isolation supplies an explicit, enforceable granularity boundary between security and non-security functions that coarser access-control schemes lack.