Security Advisory 2026-02

Mar 4, 2026 ยท Vulnerability/Incorrect Authorization Severity/low CVSS/2.3
Summary Access Token can be used to create new API key with extended lifetime
Advisory Number 2026-02
Discovery Date 03 Nov 2025
Patch Release Date 01 Dec 2025
Advisory Release Date 05 Mar 2026
Product Octopus Server
Operating System Windows and Linux
Severity Low
CVE ID CVE-2026-3236

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 2025.4.10464 or higher are not affected.

Severity

Octopus Deploy has given this vulnerability a low 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 versions of Octopus Server it was possible to create a new API key from an existing access token resulting in the new API key having a lifetime exceeding the original API key used to mint the access token.

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 2025.3.14761
  • All 2025.4.x versions before 2025.4.10409

Fix

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

  • 2025.3.14761
  • 2025.4.10409

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 (2025.4.10464). You can download the latest version of Octopus Server from https://octopus.com/downloads

If you can't upgrade to the latest version (2025.4.10464):

If you have feature version... ...then upgrade to this version
2023.x , 2024.x 2025.3.14761 or greater
2025.1.x, 2025.2.x, 2025.3.x 2025.3.14761 or greater
2025.4.x 2025.4.10409 or greater

Mitigation

There is no known mitigation for CVE-2026-3236, 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: nguyennb