CVE-2026-52782Network attack vector

Cross-project folder hijacking via user-controlled storage ID

Published Jun 26, 2026 · Updated Jun 26, 2026

IDOR in OpenProject before 17.3.3 and in 17.4.0 allows remote authenticated users to hijack another project's managed cloud folder. The settings PATCH action accepts a victim project_folder_id and writes it into the attacker's Storages::ProjectStorage row without checking project ownership. Project-admin access to one project and a shared managed Nextcloud or OneDrive storage are required; the next sync replaces the victim folder's ACL with the attacker project's user list.

CVSS severity9.9
Critical
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IDOR in OpenProject before 17.3.3 and in 17.4.0 allows remote authenticated users to hijack another project's managed cloud folder. The settings PATCH action accepts a victim project_folder_id and writes it into the attacker's Storages::ProjectStorage row without checking project ownership. Project-admin access to one project and a shared managed Nextcloud or OneDrive storage are required; the next sync replaces the victim folder's ACL with the attacker project's user list.

The record

CVE
CVE-2026-52782
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
OpenProject GmbH
Product
OpenProject
Classifications
CWE-639, T1222
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 17.3.3
  2. Affected versionversion=>= 17.4.0, < 17.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenProject GmbH · OpenProjectversion=< 17.3.3; version=>= 17.4.0, < 17.4.1

Published CVSS scores

9.9GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1222File and Directory Permissions Modification

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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