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Insecure Direct Object Reference in Project Storage Administrition Theft & Pre-Auth Remote Folder Deletion

Critical
klaustopher published GHSA-v8cr-7x8f-78mq Feb 26, 2026

Software

OpenProject

Affected versions

< 17.0.5

Patched versions

17.0.5, 17.1.2

Description

An unscoped loading of Project Storages lead to users with the Manage Files in Project permission in one project, to access project storages in other projects. This would give information about the storage that they were not supposed to see. 

Additionally, for storages with automatic project folder management, when a deletion of the project folder was triggered, the deletion in the file storage was triggered before the permission check was executed. Together with the unscoped loading above, this allowed users with Manage Files in Project permission in one project, to delete automatically managed folders in file storages that they did not have access to.

Credits

This vulnerability was reported by user cavid as part of the YesWeHack.com OpenProject Bug Bounty program, sponsored by the European Commission.

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L

CVE ID

CVE-2026-27827

Weaknesses

No CWEs