CVE-2026-63400 in Coop
Summary
by MITRE • 10/31/2026
Coop is an open source review and moderation tool from ROOST. Prior to 1.0.2, `resetPasswordForToken` updates the password row without invalidating database-backed sessions. An attacker who has acquired a password and established a session retains access even after the legitimate user resets the password, leaving the compromised account under attacker control until the session expires at its `30-day` maximum age. This issue is fixed in version 1.0.2.
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Analysis
by VulDB Data Team • 10/31/2026
The vulnerability identified in Coop versions prior to 1.0.2 represents a critical failure in session management and authentication state synchronization, specifically within the password reset functionality. As an open-source review and moderation tool developed by ROOST, Coop handles sensitive user data and access controls where integrity is paramount. The core technical flaw lies in the implementation of the `resetPasswordForToken` method, which updates the stored credentials for a user account but fails to invalidate existing active sessions associated with that account. This architectural oversight creates a significant discrepancy between the authentication state reflected by the password hash and the actual session validity maintained by the application server or database-backed session store.
From an operational perspective, this flaw allows for a persistent unauthorized access scenario often referred to as session fixation or stale session persistence. When a legitimate user initiates a password reset, typically in response to suspected compromise or routine security maintenance, they expect that any prior sessions will be terminated to prevent further exploitation. However, because the system does not invalidate database-backed sessions upon credential update, an attacker who has previously acquired valid credentials and established a session retains full access to the compromised account. The attacker can continue to perform actions under the victim's identity until the session naturally expires at its maximum age of thirty days. This extended window provides ample time for data exfiltration, privilege escalation within the application context, or further lateral movement if the user holds elevated privileges.
This vulnerability aligns with CWE-613, which describes insufficient session expiration, and more specifically relates to CWE-384, Session Fixation, as it involves maintaining a valid session identifier after security-sensitive events such as password changes. In terms of the MITRE ATT&CK framework, this behavior facilitates Initial Access persistence and allows attackers to maintain footholds without needing to repeatedly exploit authentication flaws or steal new tokens. The lack of immediate session invalidation undermines the fundamental principle that changing credentials should revoke all prior authentications for that identity, thereby reducing the effectiveness of a primary remediation step in incident response scenarios.
To mitigate this vulnerability, it is essential to implement robust session management practices that ensure any change in authentication credentials results in the immediate termination of all active sessions associated with the affected user account. This can be achieved by incrementing a version counter or timestamp stored alongside the user record and validating this value against the session data during each request, thereby rendering old sessions invalid when the credential update occurs. Alternatively, explicitly deleting all existing session records for the user upon successful password reset is an effective control. Organizations relying on Coop versions prior to 1.0.2 should upgrade immediately to version 1.0.2 or later where this issue has been resolved. Until such updates are applied, administrators may consider implementing external session management controls or reducing session timeout durations as a compensating measure to limit the window of opportunity for attackers exploiting stale sessions.