Used in attacks· fix by 2026-09-149.9Critical

ConnectWise ScreenConnect

CVE-2026-84869

ConnectWise ScreenConnect contains both an improper privilege management and missing authorization vulnerability that may allow an attacker to transfer and execute files through an active remote session without authorization or host confirmation.

What this means for your business

  • It affects ConnectWise ScreenConnect. It matters if your company, or a supplier that handles your data, runs it.
  • Attackers are already using it. CISA added it to its list of flaws used in real attacks on 11 September 2026.
  • An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.7% chance of attack attempts being seen in the next 30 days, ranking above 51% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run ConnectWise ScreenConnect, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
  3. 3Treat it as urgent. US federal agencies must fix it by 14 September 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
  4. 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Required action

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’s wording, unedited. The notes it mentions are in CISA’s catalogue entry.

Scoring

CVSS
9.9 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness
CWE-269
Assigned by
7d616e1a-3288-43b1-a0dd-0a65d3e70a49

Dates

Published
2026-09-11
Last modified
2026-09-12
Added to KEV
2026-09-11
Remediation due
2026-09-14
Sources
CISA KEV, NVD

Affected products

  • Connectwise Screenconnect- 26.6.5.9742

As listed in the NVD configuration data. Not a statement about your estate.

References