# CVE-2026-46386: OpenProject Remote Code Execution via Hardcoded Secret Key in Docker

Source: https://junglewise.ai/threats/cve-2026-46386-openproject-remote-code-execution-via-hardcoded-secret-key-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-26. Updated: 2026-06-26  
License: CC BY 4.0 with a link back

CVE-2026-46386 · Severity: critical · CVSS 9.9 · Published 2026-06-26

OpenProject is a web-based project management platform. A security flaw in its official Docker images uses a predictable default security key, which can allow an attacker to take full control of the application. If self-registration is enabled, any person on the internet could potentially gain administrative access or execute malicious commands on the server, leading to total data exposure or service disruption.

## Quick answers

**Is CVE-2026-46386 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-46386 being exploited in the wild.

**How severe is CVE-2026-46386?** Critical severity, with a CVSS score of 9.9, published 26 June 2026.

**Which products and versions are affected?** opf OpenProject >= 8.3.0, < 17.2.4; >= 17.3.0, < 17.3.2; 17.4.0-dev.

**Is there a fix for CVE-2026-46386?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-46386 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-46386?** Check whether anything you run is named in the advisory. 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.

## Technical details

The official OpenProject Docker image ships with a hardcoded default environment variable 'SECRET_KEY_BASE=OVERWRITE_ME'. When this default is not overridden by the administrator, the application uses a deterministic key to sign and encrypt cookies. Because the application was configured to use 'cookies_serializer = :marshal', an attacker who knows the secret key can craft a malicious cookie containing a serialized Ruby object. When the application processes this cookie (specifically via the /my/two_factor_devices endpoint), it triggers a deserialization vulnerability (CWE-502). This can be leveraged to achieve arbitrary object injection, such as creating an administrative user or executing OS commands as the Puma worker process. The vulnerability is pre-authentication if self-registration is enabled, or post-authentication for any low-privileged user otherwise. Fixes include mandatory validation of the secret key and switching the cookie serializer to JSON.

## Affected products

- opf OpenProject >= 8.3.0, < 17.2.4; >= 17.3.0, < 17.3.2; 17.4.0-dev

## Timeline

- 2019-01-14: other: Hardcoded literal introduced in commit 57874efa23
- 2026-05-13: advisory: GitHub security advisory published by vendor
- 2026-06-26: disclosed: CVE published to NVD

## References

- [https://github.com/opf/openproject/security/advisories/GHSA-r85r-gjq2-f83r](https://github.com/opf/openproject/security/advisories/GHSA-r85r-gjq2-f83r)