CISA Adds Microsoft SharePoint Code Injection to KEV
Tech GuruQuick Answer
CVE-2026-65660 lets an authenticated, low-privilege attacker execute code on an affected SharePoint server without another user's interaction. CISA lists it as exploited. Match the farm's edition to Microsoft's updates and perform the required forensic triage; patching alone cannot show that a farm is clean.
Confirm Scope And Apply The Supported Fix
Next step: Check every farm server, its SharePoint edition and build, and the current Microsoft update prerequisites. Use the supported farm-update workflow and retain evidence needed for incident review.
Last verified: 2026-09-26 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Microsoft SharePoint Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition on x64 systems |
|---|---|
| Advisory | CISA KEV: CVE-2026-65660 |
| CVE | CVE-2026-65660 |
| Authoritative release date | 2026-09-25 14:39:25.365400 UTC |
| Authority revision date | 2026-09-25 15:41:24.086 UTC |
| Affected versions | SharePoint Server 2016 builds before 16.0.5565.1001, SharePoint Server 2019 builds before 16.0.10417.20198, and Subscription Edition builds before 16.0.19725.20522. |
| Fixed version | The applicable August 2026 Microsoft security update that reaches build 16.0.5565.1001, 16.0.10417.20198, or 16.0.19725.20522 |
| CVSS base score | 8.8 (official CVSS v3.1) |
| CVSS severity | High |
| Exploitation status | CISA lists exploitation in the wild and requires forensic triage for this KEV entry. That does not establish compromise of a particular farm; the ransomware-use field is Unknown. |
What Changed
The recorded KEV entry added urgency to an already documented Microsoft fix. Its remediation deadline applies to organizations covered by the relevant federal directive, not automatically to every site owner. Other operators should prioritize by exposure and business risk without waiting for a regulatory deadline.
What To Validate Now
- Inventory. Locate Microsoft SharePoint Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition on x64 systems deployments, versions, enabled features, exposure paths, owners, and dependent services.
- Establish applicability. Compare each deployment with the authority's affected-version statement: SharePoint Server 2016 builds before 16.0.5565.1001, SharePoint Server 2019 builds before 16.0.10417.20198, and Subscription Edition builds before 16.0.19725.20522. Do not infer applicability from product family or severity alone.
- Remediate. Microsoft lists KB5002905 and KB5002906 for SharePoint 2016 (16.0.5565.1001), KB5002894 and KB5002896 for 2019 (16.0.10417.20198), and KB5002893 for Subscription Edition (16.0.19725.20522). Apply all applicable updates offered for the installed software, not one arbitrarily selected package from a pair. Follow the farm-update procedure and current prerequisites in Microsoft's advisory record.
- Validate. Confirm farm-wide build consistency and completion of required configuration steps. Test authentication, representative sites, document access, and integrations. Preserve suspicious logs and post-update evidence; a healthy site response alone cannot rule out earlier compromise.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
