CVE-2026-46386: OpenProject: Pre-authentication RCE in openproject/openproject Docker image via default `SECRET_KEY_BASE=OVERWRITE_ME` and `cookies_serializer = :marshal`

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-26 · updated 2026-10-25
Weakness: CWE-502

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 .

Affected products

opf openproject: from 8.3.0, < 17.2.4; from 17.3.0, < 17.3.2

References

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

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