Auth bypass in Openproject
CVE-2026-40896
OpenProject is open-source, web-based project management software. Prior to version 17.3.0, a user with `manage_agendas` permission in any project can inject agenda items into meetings belonging to any other project on the instance — even projects they have no access to. No knowledge of the target project, meeting, or victim is required; the attacker can blindly spray items into every meeting on the instance by iterating sequential section IDs. Version 17.3.0 patches the issue.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (13.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
- Openproject
- Opf Openproject — versions < 17.3.0
Weakness classification (CWE)
References
- github.com/opf/openproject/security/advisories/GHSA-hh5p-gwf8-h245 (Exploit, Mitigation, Vendor Advisory)
- github.com/opf/openproject/commit/8f693a1f35d0a84bb69af78fb6925f74329ae4fe (Patch)
Frequently asked questions
- What is CVE-2026-40896?
- CVE-2026-40896 is a medium-severity vulnerability in Openproject, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.5/10. Published 2026-04-20.
- How severe is CVE-2026-40896?
- Medium severity. CVSS v3 base score is 6.5 out of 10.