# CVE-2026-90866: Progress Software WS_FTP Server path traversal

Source: https://junglewise.ai/threats/cve-2026-90866-a-path-traversal-vulnerability-in-progress-software-ws-ftp-server  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-90866 · Severity: critical · CVSS 9.1 · Published 2026-10-29

WS_FTP Server is a file transfer application used by organizations to securely exchange files. A delegated Host Administrator can exploit a path traversal vulnerability to access files and directories outside their authorized scope, potentially leading to remote code execution and full system compromise.

Technologies: [Progress Software WS FTP Server](https://junglewise.ai/threats/technologies/progress-software-ws-ftp-server). Vendors: [Progress Software](https://junglewise.ai/threats/vendors/progress-software).

## Quick answers

**Is CVE-2026-90866 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90866 being exploited in the wild.

**How severe is CVE-2026-90866?** Critical severity, with a CVSS score of 9.1, published 29 October 2026.

**Which products and versions are affected?** Progress Software WS FTP Server prior to 2024.0.7 and 2025.0.4.

**Is there a fix for CVE-2026-90866?** Yes: fixed in WS_FTP Server 2024.0.7, 2025.0.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-90866 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-90866?** Check whether you run Progress Software WS FTP Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in WS_FTP Server 2024.0.7, 2025.0.4

## Technical details

A path traversal vulnerability in WS_FTP Server allows a delegated Host Administrator to bypass directory restrictions and access arbitrary locations on the Windows system. The vulnerability requires valid administrative credentials but does not require additional user interaction. Successful exploitation could enable remote code execution with the privileges of the FTP service.

## Affected products

- Progress Software WS_FTP Server prior to 2024.0.7 and 2025.0.4

## Timeline

- 2026-10-29: disclosed

## References

- [https://progress.lightning.force.com/lightning/r/Knowledge__kav/ka7Pb000001vl86IAA/view](https://progress.lightning.force.com/lightning/r/Knowledge__kav/ka7Pb000001vl86IAA/view)

## Related threats

- [Progress Software WS_FTP Server access restriction bypass in Thin Client Web Transfer](https://junglewise.ai/threats/cve-2026-115341-improper-access-restrictions-in-the-thin-client-web-transfer)
- [Progress Software WS_FTP Server sensitive data exposure in temp file](https://junglewise.ai/threats/cve-2026-115340-progress-software-ws-ftp-server-versions-prior-to-2025-0-5-on)
- [Progress Software WS_FTP Server denial of service via insufficient resource limits](https://junglewise.ai/threats/cve-2026-115339-insufficient-resource-limits-in-progress-software-ws-ftp-server)
- [Progress WS_FTP Server incorrect quota accounting](https://junglewise.ai/threats/cve-2026-115336-incorrect-quota-accounting-in-progress-software-ws-ftp-server)
- [Progress Software WS_FTP Server code injection in Manager web console](https://junglewise.ai/threats/cve-2026-90872-improper-neutralization-of-directives-in-dynamically-evaluated)