CVE-2026-52779

Description

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.

CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.08%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-639 CWE-639

CWE-863 Incorrect Authorization

References

Other References

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

Frequently Asked Questions

What is CVE-2026-52779? +

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. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-52779? +

CVE-2026-52779 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-52779? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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