CVE-2026-44731: OpenProject: Improper Access Control on OpenProject through /projects/[projectName]/meetings via "invited_user_id" in GET parameter "filters" leads to user names disclosure

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% 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-639

Description

OpenProject is open-source, web-based project management software. Prior to 17.3.2 and 17.4.0, the web application's meetings filter feature leaks whether a given user ID corresponds to a valid account and discloses the user's full name, allowing an attacker to enumerate all existing user accounts by probing user IDs and observing differences in the server response. This vulnerability is fixed in 17.3.2 and 17.4.0.

Affected products

opf openproject: before 17.3.2

References

https://github.com/opf/openproject/security/advisories/GHSA-x7j3-cfgf-7mc4

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