CVE-2026-65660
HIGH 8.8 KNOWN EXPLOITED ALL-YEARSImproper control of generation of code ('code injection') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Confirmed exploited in the wild — in CISA KEV since 2026-09-25. Patch or mitigate now.
Exploitation likelihood
8.2%chance of exploitation in 30 days · 95th percentile
Impact if exploited
8.8CVSS 3.1 · HIGH · CNA
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Affected
Vendors Microsoft
Products Microsoft Sharepoint Enterprise Server 2016 Microsoft Sharepoint Server 2019 Microsoft Sharepoint Server Subscription Edition Sharepoint Server
Weakness (CWE)
- CWE-94: : Improper Control of Generation of Code ('Code Injection')
CVSS 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 and research data (JSON)
Unverified PoC candidates
Catalogue matches for further research. These repositories have not been validated as working exploits.
2 candidates
- https://github.com/HORKimhab/CVE-2026-65660
CVE-2026-65660 - Draft or TODO
PoC-in-GitHub · CVE-2026-65660
PoC-in-GitHub · CVE-2026-65660 · Updated 2026-09-25T03:31:25Z - https://github.com/ShadowForge-Cyber/CVE-2026-65660-Poc
Malicious Register Directive Code Injection Exploit
PoC-in-GitHub · CVE-2026-65660
PoC-in-GitHub · CVE-2026-65660 · Updated 2026-09-25T20:32:48Z
Additional exploitation reports
Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.
- ENISA EU KEV · 2026-09-25EUVD · EUVD-2026-56431
- VulnCheck KEV · 2026-09-24T00:00:00Z
Source 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.
Source ransomware assessment: Unknown
VulnCheck KEV · CVE-2026-65660 · Updated 2026-09-24T00:00:00Z - VulnCheck KEV · 2026-09-24T00:00:00ZVulnCheck KEV · CVE-2026-65660
- VulnCheck KEV · 2026-09-25T00:00:00ZVulnCheck KEV · CVE-2026-65660
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Sharepoint Server | < 16.0.19725.20522 |
| Microsoft | Sharepoint Server | 2016 |
| Microsoft | Sharepoint Server | 2019 |
All CVSS metrics
- HIGH 8.8 v3.1 · CNA Primary
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 - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65660 CVE record · microsoft · Updated 2026-10-21T20:52:28.070Z
NVD · CVE-2026-65660 · Updated 2026-09-26T04:17:45.630
Advisories
- https://blog.previdian.com/cve-2026-65660-previdian-observes-two-stage-sharepoint-exploitation-attempts/ CVE record · CISA-ADP · Updated 2026-09-26T03:55:40.674Z
NVD · CVE-2026-65660 · Updated 2026-09-26T04:17:45.630 - https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-65660 CVE record · CISA-ADP · Updated 2026-09-26T03:55:40.674Z
NVD · CVE-2026-65660 · Updated 2026-09-26T04:17:45.630 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-56431 EUVD · EUVD-2026-56431
- https://vulncheck.com/kev VulnCheck KEV · CVE-2026-65660 · Updated 2026-09-24T00:00:00Z
Technical & other
- https://previdian.com/CVE-2026-65660 VulnCheck KEV · CVE-2026-65660 · Updated 2026-09-24T00:00:00Z
- https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json VulnCheck KEV · CVE-2026-65660 · Updated 2026-09-24T00:00:00Z
Sources: NVD · CVE.org · All sources and attribution · EPSS