CVE-2019-2386 in MongoDB
Summary
by MITRE
After user deletion in MongoDB Server the improper invalidation of authorization sessions allows an authenticated user's session to persist and become conflated with new accounts, if those accounts reuse the names of deleted ones. This issue affects MongoDB Server v4.0 versions prior to 4.0.9; MongoDB Server v3.6 versions prior to 3.6.13 and MongoDB Server v3.4 versions prior to 3.4.22.
Workaround: After deleting one or more users, restart any nodes which may have had active user authorization sessions.
Refrain from creating user accounts with the same name as previously deleted accounts.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability described in CVE-2019-2386 represents a critical authorization session management flaw in MongoDB server implementations across multiple version lines. This issue stems from inadequate session invalidation mechanisms that occur when user accounts are removed from the system, creating a persistent security risk that can be exploited by malicious actors. The flaw allows for session hijacking scenarios where deleted user sessions remain active and can be leveraged by attackers who subsequently create accounts with identical usernames, effectively enabling unauthorized access to systems that should be restricted to legitimate users. The vulnerability specifically impacts MongoDB Server versions 4.0 prior to 4.0.9, 3.6 prior to 3.6.13, and 3.4 prior to 3.4.22, representing a significant portion of the MongoDB ecosystem that was vulnerable to this particular authorization bypass.
The technical nature of this vulnerability aligns with CWE-613, which describes insufficient session management where security-sensitive sessions do not properly invalidate when user accounts are deleted. This creates a persistent authorization state that can be exploited through session replay attacks, where an attacker who has gained access to a deleted user's session can reuse that session to gain access to newly created accounts sharing the same username. The flaw operates at the authorization layer of MongoDB's security model, specifically affecting how the server handles session invalidation during user deletion operations. When a user account is deleted, the system should immediately invalidate all associated authorization sessions, but in affected versions, this invalidation process fails to complete properly, leaving active sessions that can be reused by unauthorized parties.
The operational impact of this vulnerability extends beyond simple unauthorized access, creating potential for privilege escalation and persistent backdoors within MongoDB deployments. Attackers can exploit this weakness by deleting legitimate user accounts and then creating new accounts with identical names, effectively bypassing the authentication controls that should prevent unauthorized access to sensitive data and system resources. This creates a particularly dangerous scenario for environments where user accounts are frequently created and deleted, as it allows for continuous exploitation opportunities. The vulnerability also affects database administrators who may not immediately recognize that deleted sessions can persist and be reused, potentially leading to extended periods of unauthorized access without detection. Security monitoring systems that rely on user account lifecycle management may not detect this anomaly since the session appears legitimate from an authentication standpoint.
Organizations affected by CVE-2019-2386 should implement immediate mitigations including the mandatory restart of MongoDB nodes that may have had active user sessions when deletions occurred, as specified in the workaround guidance. This restart process ensures that all stale authorization sessions are cleared from memory and that the system operates with a clean authorization state. Additionally, administrators should implement strict policies against reusing usernames from previously deleted accounts, which directly addresses the root cause of the vulnerability by preventing the creation of session collision scenarios. The recommended approach aligns with ATT&CK technique T1078.004, which covers valid accounts with reused credentials, as this vulnerability essentially allows for credential reuse in an unauthorized context. Organizations should also consider implementing additional monitoring controls to detect unusual user account deletion and recreation patterns, as these activities may indicate exploitation attempts. The fix for this vulnerability required MongoDB to properly implement session invalidation procedures during user deletion operations, ensuring that all associated authorization tokens and session identifiers are immediately revoked and cannot be reused for authentication purposes.