CVE-2026-12887: Octopus Server path traversal in NuGet package deployment

CVE-2026-12887 · Severity: info · Published 2026-10-27

Octopus Server is a deployment automation platform used to orchestrate application releases. An attacker with permission to upload NuGet packages can exploit a path traversal flaw to execute scripts outside the intended deployment directory, potentially gaining unauthorized access to other parts of the system or sensitive data.

Technologies: Octopus Deploy Octopus Server. Vendors: Octopus Deploy.

Quick answers

Is CVE-2026-12887 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-12887 being exploited in the wild.
How severe is CVE-2026-12887?
Informational severity, published 27 October 2026.
Which products and versions are affected?
Octopus Deploy Octopus Server 2023.x, 2024.x, 2025.x, 2026.1 before 2026.1.674, 2026.2 before 2026.2.973, 2026.3 before 2026.3.5839.
Is there a fix for CVE-2026-12887?
Yes: fixed in Octopus Server 2026.1.674, 2026.2.973, 2026.3.5839 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-12887 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-12887?
Check whether you run Octopus Deploy Octopus 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: Octopus Server 2026.1.674, 2026.2.973, 2026.3.5839 or later

Technical details

A path traversal vulnerability in Octopus Server allows a user with NuGet package upload permissions to craft a malicious package that causes script steps to execute outside their parent directory. The vulnerability affects versions 2023.x through 2026.2 and early 2026.3 releases, requiring authenticated access and package upload capability. Exploitation permits arbitrary script execution in unintended filesystem locations.

Affected products

  • Octopus Deploy Octopus Server 2023.x, 2024.x, 2025.x, 2026.1 before 2026.1.674, 2026.2 before 2026.2.973, 2026.3 before 2026.3.5839

Timeline

  • 2026-06-14: disclosed: Discovery date
  • 2026-07-09: patched: Patch release date
  • 2026-10-27: advisory: Advisory published

References

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