CVE-2026-65660
Improper control of generation of code ('code injection') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
do firstApply 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.
Can a WAF block it? Partly. Code injection payloads are often obfuscated, so they slip past generic WAF rules.
Also consider: remove eval sinks · RASP
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2026-65660 being exploited?
Yes. CVE-2026-65660 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2026-65660?
CVE-2026-65660 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-65660?
Yes. A fix has been recorded for CVE-2026-65660. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-65660 affect?
CVE-2026-65660 affects microsoft:sharepoint_server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected>= 16.0.0 and < 16.0.5565.1001
- affected>= 16.0.0 and < 16.0.10417.20198
- affected>= 16.0.0 and < 16.0.19725.20522
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Unvetted proof-of-concept code on GitHub: 2 GitHub proofs of concept
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- no
- technical impact
- total
Assessed by CISA 24 Sept 2026 (SSVC 2.0.3).
timeline
- 11 Aug 2026Published
- 24 Sept 2026CISA SSVC assessment: exploitation active · 43 days later
- 25 Sept 2026Added to CISA KEV (exploited in the wild) · 1 day later
- 25 Sept 2026First proof-of-concept repository on GitHub (unvetted) · same day later
- 28 Sept 2026CISA remediation due date (US federal agencies) · 3 days later
- 30 Oct 2026CVE record last updated · 33 days later
- 2 Nov 2026Analysed by vulneraibility.com · 3 days later
- Advisoryblog.previdian.com /cve-2026-65660-previdian-observes-two-stage-sharepoint-exploitation-attempts/
- Patchmsrc.microsoft.com /update-guide/vulnerability/CVE-2026-65660
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-65660
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.