# CVE-2026-90871: Progress Software WS_FTP Server path traversal

Source: https://junglewise.ai/threats/cve-2026-90871-improper-limitation-of-a-pathname-to-a-restricted-directory-in  
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-2026-90871 · Severity: medium · CVSS 5.3 · Published 2026-10-29

WS_FTP Server is a file transfer service used by organizations to securely exchange files. An unauthenticated attacker can exploit a path traversal vulnerability to access and modify files outside the intended restricted directory on Windows systems, potentially compromising sensitive data or system integrity.

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-2026-90871 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90871 being exploited in the wild.

**How severe is CVE-2026-90871?** Medium severity, with a CVSS score of 5.3, 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-2026-90871?** 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-2026-90871 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-90871?** 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

An improper pathname restriction flaw in WS_FTP Server allows unauthenticated remote attackers to traverse outside the intended FTP directory hierarchy. The vulnerability stems from inadequate validation of file path inputs, enabling unauthorized access to arbitrary files on the affected Windows system without requiring authentication.

## 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)