Actively exploited · Published Aug 11, 2026 · Assigned by microsoft

CVE-2026-65660Microsoft SharePoint Server Remote Code Execution Vulnerability

High 8.8 Exploited

In plain English

A high-severity code injection in Microsoft SharePoint Enterprise Server 2016 from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on September 25, 2026). The chance it is exploited in the next 30 days is estimated at 8.2% (higher than 95% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)8.2%top 5.1% of all CVEs
Exploited in the wildYesCISA KEV since Sep 25, 2026
Attack tooling1Public PoC

CISA guidance

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Federal agencies must remediate by Sep 28, 2026.

Official description

Improper control of generation of code ('code injection') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Affected products (as reported)

VendorProductVersions
Microsoft Microsoft SharePoint Enterprise Server 2016 16.0.0 – before 16.0.5565.1001
Microsoft Microsoft SharePoint Server 2019 16.0.0 – before 16.0.10417.20198
Microsoft Microsoft SharePoint Server Subscription Edition 16.0.0 – before 16.0.19725.20522

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

References