CVE-2026-40365Critical
Microsoft SharePoint Server Remote Code Execution Vulnerability
Assessment
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
- Severity
- Critical
- CVSS base score
- 8.8CVSS:3.1/
AV:N/ AC:L/ PR:L/ UI:N/ S:U/ C:H/ I:H/ A:H/ E:U/ RL:O/ RC:C - Impact
- Remote Code Execution
- EPSS, next 30 days
- 1.1%Higher than 62.9% of scored CVEs · FIRST model run 29 Sep 2026 · about EPSS
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Exploitation Less Likely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Microsoft Office SharePoint
- Weakness
- CWE-1220: Insufficient Granularity of Access Control
- Issued by
- Microsoft
- Published
- 12 May 2026 · May 2026
- Last revised
- 12 May 2026
Updates that fix it
3 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5002863 | Security Update | — | Microsoft SharePoint Server Subscription Edition | All CVEs in KB5002863 |
| KB5002868 | Security Update | — | Microsoft SharePoint Enterprise Server 2016 | All CVEs in KB5002868 |
| KB5002870 | Security Update | — | Microsoft SharePoint Server 2019 | All CVEs in KB5002870 |