Security Advisory 2026-01

Summary File Modification/Deletion Path Traversal
Advisory Number 2026-01
Discovery Date 06 Jan 2026
Patch Release Date 23 Jan 2026
Advisory Release Date 25 Feb 2026
Product Octopus Server
Operating System Windows and Linux
Severity Medium
CVE ID CVE-2026-0704

Customers who have downloaded and installed any of the Octopus Server versions listed below ("Details") are affected.

Please upgrade your Octopus Server immediately to fix this vulnerability.

Customers who have upgraded Octopus Server to version 2025.4.10446 or higher are not affected.

Severity

Octopus Deploy has given this vulnerability a medium rating. This rating was given according to the Octopus Deploy severity levels, which ranks vulnerabilities as critical, high, medium, or low severity.

This is our assessment and you should evaluate its applicability to your own environment.

Details

In affected version of Octopus Deploy it was possible to remove files and/or contents of files on the host using an API endpoint. The field lacked validation which could potentially result in ways to circumvent expected workflows.

The versions of Octopus Server affected by this vulnerability are:

  • All 2023.x versions
  • All 2024.x versions
  • All 2025.1.x, 2025.2.x versions
  • All 2025.3.x versions before 2025.3.14715

Fix

To address this vulnerability, we have released Octopus Server version:

  • 2025.3.14715
  • 2025.4.10359

The latest versions of Octopus Deploy products can be downloaded from https://octopus.com/downloads and previous versions can be downloaded from https://octopus.com/downloads/previous

What You Need to Do

Octopus Deploy recommends that you upgrade to the latest version (2025.4.10446). You can download the latest version of Octopus Server from https://octopus.com/downloads

If you can't upgrade to the latest version (2025.4.10446):

If you have feature version... ...then upgrade to this version
2023.x , 2024.x 2025.3.14715 or greater
2025.1.x, 2025.2.x, 2025.3.x 2025.3.14715 or greater
2025.4.x 2025.4.10359 or greater

Mitigation

There is no known mitigation for CVE-2026-0704, it is important to upgrade to a fixed version as soon as possible.

Support

If you have any questions or concerns regarding this advisory, please contact our support team https://octopus.com/support.

Exploitation and Public Announcements

The Octopus Deploy security team is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

This vulnerability was found by Bugcrowd Researcher: oub3ll4