Actively exploited · Published Sep 8, 2026 · Assigned by ConnectWise
CVE-2026-84869ScreenConnect Client: Guest-to-Host File Execution via File-Transfer Actions
Critical 9.9 Exploited
In plain English
A critical-severity missing authorization in ScreenConnect from ConnectWise. Attackers are actively exploiting it in the wild (listed by CISA on September 11, 2026). The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). 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.
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 14, 2026.
Official description
A condition in the ScreenConnect client may allow files to be transferred and executed through an active remote session without authorization or Host confirmation in certain circumstances. ScreenConnect servers are not impacted.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ConnectWise | ScreenConnect | All versions prior to 26.6.5 |
Weakness: CWE-862, CWE-269 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
References
- https://www.connectwise.com/company/trust/security-bulletins/2026-09-08-screenconnect-bulletin
- https://github.com/ConnectWise-Advisories/Disclosures/tree/main/CVE-2026-84869
- https://www.connectwise.com/company/trust/advisories
- https://www.huntress.com/blog/rogue-screenconnect-installations third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-84869 government-resource