OpenProject: Cross-project authorization bypass allows deleting public Calendar and Team Planner queries from unauthorized projects

published 2026-06-26 4 mo ago modified 2026-10-25 15 d ago also EUVD-2026-39873

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits: 0; none known

OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, a cross-project IDOR / authorization context confusion in the Calendar and Team Planner modules allows a user with management permissions in one project to delete public Calendar or Team Planner Queries from another project where they do not have the corresponding management permissions. Both modules authorize the request against the project identified by :project_id in the URL, but the actual Query object is loaded later by :id from Query.visible(current_user) without verifying that the loaded Query belongs to the authorized project. As a result, an attacker can use permissions from Project A to delete shared/public Calendar or Team Planner views from Project B, causing integrity impact and limited availability impact for users relying on those shared views. This vulnerability is fixed in 17.3.3 and 17.4.1.

Patch / fix

fixed in 1

openproject openproject 17.3.3, 17.4.1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 4 mo ago (2026-06-29)

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/opf/openproject/security/advisories/GHSA-jrx5-px3f-vfq4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

Affected products

opf openproject

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-863 Incorrect Authorization

References

github.com /opf/openproject/security/advisories/GHSA-jrx5-px3f-vfq4
exploit

Sources

CVE List CVE-2026-52779
NVD CVE-2026-52779

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary