CVE-2026-23721 affects OpenProject, an open-source, web-based project management software. The vulnerability stems from a failed permission check that permits users with the 'View Members' permission in any project to enumerate all groups and view all users within those groups. This issue was present in versions prior to 17.0.1 and 16.6.5. Organizations using older versions are at risk of exposing sensitive user information, necessitating immediate attention.
The vulnerability has been classified as medium severity with a CVSS score of 4.3, indicating a moderate risk level. The attack vector is network-based, and the complexity is low, which means that attackers could exploit this vulnerability easily if they have the requisite permissions. Organizations must prioritize patching to mitigate this risk.
The issue is significant as it allows unauthorized access to user group information, potentially leading to privacy violations and other security concerns. As of the publication date, there are no known workarounds available, which further emphasizes the urgency for affected organizations to upgrade to the fixed versions.
Organizations should address this vulnerability as part of their security maintenance schedule. The updates are available in OpenProject version 17.0.1 and 16.6.5, which rectify this permission oversight.
Vulnerability Details
The OpenProject vulnerability allows users with the 'View Members' permission to see all members of groups they should not have access to. It was discovered prior to the release of versions 17.0.1 and 16.6.5, which include the necessary fix. The CVSS score of 4.3 indicates a medium severity classification, highlighting the need for organizations to remain vigilant.
The vulnerability is classified under CWE-862, which identifies the failure to control access to sensitive information based on user permissions. This oversight can lead to unauthorized information disclosure, which is particularly concerning in environments where user data privacy is paramount.
The vulnerability was published on January 19, 2026, and is currently analyzed with a status indicating that a fix is available. Organizations utilizing OpenProject should ensure their systems are updated to mitigate any risks associated with this vulnerability.
Technical Analysis
The root cause of CVE-2026-23721 is a failed permission check within OpenProject's user group management functionality. This oversight allowed users with the 'View Members' permission to access group membership details, a function that should have been restricted. The attack vector is network-based, meaning that an attacker could exploit this vulnerability remotely.
The attack complexity is rated as low, implying that it does not require advanced skills or knowledge to exploit. Privileges required to exploit this vulnerability are low, as any user with the appropriate permissions could potentially enumerate group memberships. User interaction is not required for exploitation, adding to the vulnerability's risk.
In terms of impact, the confidentiality of user information is at risk, while integrity and availability remain unaffected. As a result, organizations should closely monitor their user permission settings and ensure that sensitive information is adequately protected.
Risk & Impact Analysis
The deployment of OpenProject with this vulnerability presents real-world risks to organizations, particularly concerning user privacy and data security. An attacker exploiting this vulnerability could gain insights into user roles and associations, which can be leveraged for further attacks or social engineering tactics.
With a CVSS score of 4.3, the urgency for organizations to patch this vulnerability falls into a medium-high category. Organizations should incorporate this remediation into their priority patch cycle to mitigate the risks associated with unauthorized data exposure.
As the vulnerability does not directly impact system integrity or availability, organizations may perceive it as less critical compared to other vulnerabilities. However, the potential for unauthorized access to sensitive information means that it should not be overlooked.
The blast radius for this vulnerability is significant, as it could affect multiple users and groups within OpenProject if left unpatched. Organizations should ensure that their user management practices are robust and that they promptly apply necessary updates.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
OpenProject versions prior to 17.0.1 and 16.6.5 are affected by this vulnerability. Organizations using these versions should upgrade to the latest version to ensure their systems are not compromised.
Mitigation & Remediation
To mitigate the risks associated with CVE-2026-23721, organizations should upgrade to OpenProject version 17.0.1 or 16.6.5. If immediate patching is not possible, organizations should review their user permission settings and limit the 'View Members' permission to only those users who genuinely require it.
Additionally, organizations may consider implementing network segmentation to restrict access to sensitive user information and monitor for any unauthorized access attempts. Regular security audits can help identify and rectify permission-related vulnerabilities.
For further assistance in enhancing security posture, organizations can engage in penetration testing activities that simulate real-world attacks and help identify vulnerabilities.
Detection Guidance
Organizations should monitor logs for any unusual activity related to user permissions and group management. Indicators of compromise may include unauthorized changes to group memberships or unusual access patterns by users with 'View Members' permission.
Behavioral anomalies, such as users accessing groups they should not have visibility into, should also be flagged for review. Network signatures that indicate unauthorized enumeration attempts should be implemented to alert security teams of potential exploitation.
AppSecure Threat Intelligence Insight
CVE-2026-23721 highlights the ongoing challenges organizations face in managing user permissions effectively. As vulnerabilities related to access controls continue to arise, security teams must adopt a proactive approach to user management and regularly review permissions to ensure compliance with the principle of least privilege.
This vulnerability serves as a reminder of the importance of thorough security assessments and timely patching. Organizations should stay informed about security trends and consider adopting a vulnerability management program that emphasizes not only remediation but also the identification and prioritization of risks.
Organizations can also benefit from targeted penetration testing methodologies that evaluate existing security measures and reveal any gaps in their defenses.
Finally, organizations should consider participating in security testing best practices discussions to share insights and stay ahead of emerging threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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