CVE-2026-23721 | OpenProject users with "View Members" permission in any project can view all Group memberships

OpenProject is an open-source, web-based project management software. When using groups in OpenProject to manage users, the group members should only be visible to users that have the View Members permission in any project that the group is also a member of. Prior to versions 17.0.1 and 16.6.5, due to a failed permission check, if a user had the View Members permission in any project, they could enumerate all Groups and view which other users are part of the group. The issue has been fixed in OpenProject 17.0.1 and 16.6.5. No known workarounds are available.

Published: 2026-01-19 Last update: 2026-02-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-23721 is rated Low Risk (19.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23721

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.18% +0.15%
2 2026-01-20 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 1.4 [email protected]

Weakness enumeration for CVE-2026-23721

Affected software / configurations for CVE-2026-23721

Vendor Product Version Raw CPE
openproject openproject < 16.6.5 cpe:2.3:a:openproject:openproject:*:*:*:*:*:*:*:*
openproject openproject 17.0.0 cpe:2.3:a:openproject:openproject:17.0.0:*:*:*:*:*:*:*

References for CVE-2026-23721

cvelogic Threat Intelligence