CVE-2026-23646 affects OpenProject, an open-source, web-based project management software. This vulnerability allows users of OpenProject versions prior to 16.6.5 and 17.0.1 to unauthenticate other users by improperly deleting their active sessions. Specifically, the issue arises from the lack of checks to verify that a session belongs to the user attempting to delete it.
The vulnerability has a CVSS score of 6.5, categorizing it as medium severity. The risk to organizations includes unauthorized session terminations, potentially disrupting user workflows. Although users cannot access sensitive information from other sessions, the ability to terminate sessions still poses a significant operational risk.
The issue was publicly disclosed on January 19, 2026, and was patched in versions 16.6.5 and 17.0.1. Organizations using affected versions must prioritize patching immediately to mitigate this vulnerability.
As this vulnerability is not included in the Known Exploited Vulnerabilities (KEV) catalog, there are currently no known active exploitation attempts. However, organizations should remain vigilant.
Remediation does not have known workarounds since the vulnerability does not require specific permissions that could be temporarily disabled. The only effective measure for organizations is to upgrade to the patched versions.
Vulnerability Details
The CVE-2026-23646 vulnerability allows users to view and end their active sessions via Account Settings → Sessions. When a session is deleted, the system fails to check if the session belongs to the user, allowing users to unauthenticate others by iterating requests using `DELETE /my/sessions/:id`.
The vulnerability affects OpenProject versions prior to 16.6.5 and 17.0.1. The official CVSS score for this vulnerability is 6.5, indicating a medium severity level. The attack vector is network-based, with low complexity and requiring low privileges.
The vulnerability is categorized under CWE-488, indicating a failure to properly check ownership of objects and actions.
Technical Analysis
The root cause of CVE-2026-23646 stems from inadequate verification that a user owns the session they are attempting to delete. In this scenario, the session ID, which is based on incremental integers, can be guessed and manipulated by users.
The attack vector is network-based, meaning that no local access is required to exploit the vulnerability. The complexity of the attack is low, as users can easily construct the required DELETE requests without significant technical expertise.
Privileged access is required at a low level since the user must be logged into their account. There is no need for user interaction during the attack, as the exploitation can be performed directly through the API.
The vulnerability has a high availability impact, as it can disrupt normal user access to the application by logging users out unexpectedly. However, there is no impact on confidentiality or integrity, as users do not gain access to sensitive information from other sessions.
Risk & Impact Analysis
The real-world risk associated with CVE-2026-23646 is primarily operational. Organizations using affected versions of OpenProject face the potential for unauthorized logouts, which can disrupt project management activities and hinder productivity.
The blast radius for this vulnerability is limited to the users of the affected applications, but given that it allows any authenticated user to unauthenticate others, the potential negative impact can be significant within collaborative environments.
Given the CVSS score of 6.5, organizations should address this vulnerability in their priority patch cycle. Prompt action is essential to prevent potential operational disruptions.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
OpenProject versions prior to 16.6.5 and 17.0.1 are affected by this vulnerability. Organizations must ensure they update to these versions or later to mitigate the risk.
Mitigation & Remediation
Organizations should prioritize patching by upgrading to OpenProject versions 16.6.5 or 17.0.1. Without these updates, users will remain vulnerable to the risk of unauthorized session terminations.
For ongoing protection, organizations can implement monitoring solutions to track session management activities and identify any unauthorized session manipulations.
For additional insights into effective security practices, organizations may consider reviewing their penetration testing strategies.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor application logs for unusual session deletion requests. Behavioral anomalies such as unexpected logouts or session terminations can also indicate malicious activities.
Network signatures can be established to track unauthorized access attempts, particularly for session management endpoints. It is crucial to review any changes to user sessions that seem out of the ordinary.
AppSecure Threat Intelligence Insight
In summary, CVE-2026-23646 highlights a common issue in session management within web applications. The incremental nature of session IDs can lead to vulnerabilities if not properly secured. This incident serves as a reminder for security teams to regularly audit their session handling mechanisms.
Organizations should also consider integrating comprehensive security frameworks to preemptively identify and mitigate similar vulnerabilities. For further reading on security best practices, consider reviewing our blog on penetration testing methodology and vulnerability management programs.
Additionally, exploring topics such as API security testing can provide valuable insights into strengthening application defenses.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)