CVE-2026-52779: OpenProject is open-source, web-based project management software.

OpenProject is open-source, web-based project management software.

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.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses openproject, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.22%, higher than 12% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

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Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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