Auth bypass in Opf Openproject
CVE-2026-67528
OpenProject is open-source, web-based project management software. Prior to 17.6.0, GET /api/v3/custom_options/:id resolved CustomOption records by global numeric id and allowed UserCustomField and GroupCustomField options without checking visible(current_user), so authenticated non-admin users could enumerate sequential custom option ids and read labels belonging to admin_only user or group custom fields. This issue is fixed in 17.6.0.
Vulnerability class: Broken Access Control
EPSS: 0.002 (11.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Opf Openproject — versions < 17.6.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-67528?
- CVE-2026-67528 is a medium-severity vulnerability in Opf Openproject, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-07-30.
- How severe is CVE-2026-67528?
- Medium severity. CVSS v3 base score is 4.3 out of 10.