CVE-2026-65660
Microsoft SharePoint Code Injection Vulnerability
Microsoft SharePointApplications & CMS
CVSS
8.8HighExploit odds (EPSS)2.10%Chance of exploitation activity in the next 30 days, higher than 81% of CVEs. Scored 23 Oct 2026FIRST EPSS
CISA required actionApply 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. CISA KEV
Patching is not enoughCISA requires federal agencies to look for signs of compromise on affected systems, not only patch (forensic triage under BOD 26-04). Treat exposed systems as possibly compromised. CISA guidance
What fixes it
- 16.0.5565.1001Microsoft SharePoint Enterprise Server 2016CVE List
- 16.0.10417.20198Microsoft SharePoint Server 2019CVE List
- 16.0.19725.20522Microsoft SharePoint Server Subscription EditionCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Timeline
Description
Microsoft SharePoint contains a code injection vulnerability which could allow an authorized attacker to execute code over a network.
Text from CVE List
Affected versions 3
- Microsoft SharePoint Enterprise Server 2016affected: 16.0.0 before 16.0.5565.1001CVE List
- Microsoft SharePoint Server 2019affected: 16.0.0 before 16.0.10417.20198CVE List
- Microsoft SharePoint Server Subscription Editionaffected: 16.0.0 before 16.0.19725.20522CVE List
References 4
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65660Fixvia CVE List
- blog.previdian.com/cve-2026-65660-previdian-observes-two-stage-sharepoint-exploitation-attempts/Advisoryvia CVE List
- nvd.nist.gov/vuln/detail/CVE-2026-65660Referencevia CISA KEV
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-65660Referencevia CVE List