Auth bypass in Opf Openproject

CVE-2026-44736

OpenProject is open-source, web-based project management software. Prior to 17.4.0, the GET /api/v3/relations endpoint allows any authenticated user to retrieve relations — and the subject (title) of work packages they have no permission to view — by supplying an arbitrary work package ID in the involved, fromId, or toId filter. This bypasses the Relation.visible scope due to a flawed performance optimization in RelationQuery. This vulnerability is fixed in 17.4.0.

Vulnerability class: Information Disclosure

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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-44736: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44736?
CVE-2026-44736 is a medium-severity vulnerability in Opf Openproject, classified under Information Disclosure. CVSS score: 6.5/10. Published 2026-06-26.
How severe is CVE-2026-44736?
Medium severity. CVSS v3 base score is 6.5 out of 10.