CVE-2026-82053 in Server
Summary
by MITRE • 09/08/2026
A security issue exists in MongoDB's LDAP authorization integration where pooled LDAP connections can retain stale authentication identities after user authentication under certain configurations. Subsequent authorization queries may execute under an unintended LDAP identity rather than the expected one. This can result in incorrect role assignments based on the LDAP directory's access control configuration, potentially allowing an authenticated user to acquire elevated privileges that were not intended by the deployment's authorization policy.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability described involves a critical flaw within MongoDB’s Lightweight Directory Access Protocol (LDAP) integration mechanism, specifically concerning connection pooling and identity management during authentication sequences. In environments where LDAP is utilized as an external source for user authentication and role mapping, MongoDB maintains a pool of active connections to the directory server to optimize performance by avoiding the overhead of establishing new TCP sessions for every request. The core technical flaw lies in how these pooled connections handle state retention after a user has successfully authenticated. Under specific configuration scenarios, particularly when connection pooling is enabled with certain timeout or idle settings, the system fails to properly clear or invalidate the authentication context associated with a given LDAP connection object once that session concludes or before it is reassigned to a new client request. This results in the persistence of stale authentication identities within the pooled resource, creating a state leakage scenario where the internal representation of who is authenticated does not align with the actual user initiating the subsequent database operation.
From an operational perspective, this flaw leads directly to authorization bypass and privilege escalation. When a new user connects to MongoDB, the system may reuse one of these existing LDAP connections from the pool rather than creating a fresh one. Because the connection retains the authentication identity of the previous user who utilized it, any subsequent authorization queries executed by the new user are evaluated against the stale credentials embedded in that connection object. Consequently, the database engine determines roles and permissions based on the old user’s attributes within the LDAP directory rather than those of the current requester. If the previous user held administrative privileges or access to sensitive data collections, the newly authenticated user inherits these elevated rights unintentionally. This effectively allows an attacker with valid but lower-privileged credentials to exploit this state confusion to perform actions reserved for high-level administrators, such as modifying system configurations, accessing restricted databases, or altering security policies, thereby completely undermining the intended access control model of the deployment.
This vulnerability aligns closely with CWE-284 Improper Access Control and CWE-613 Insufficient Session Expiration, as it involves a failure to properly manage session state and identity context within pooled resources. In terms of threat modeling frameworks like MITRE ATT&CK, this behavior facilitates lateral movement and privilege escalation techniques where an adversary leverages existing valid credentials or system states to gain unauthorized access. The exploitation does not require complex binary exploits or memory corruption; instead, it relies on timing and configuration specifics that allow the stale identity to be retrieved before being overwritten by a fresh authentication handshake. This makes the vulnerability particularly dangerous in high-throughput environments where connection reuse is frequent, as the window for successful exploitation remains open during the lifecycle of pooled connections until they are explicitly closed or their state is forcibly reset.
Mitigation strategies must focus on ensuring strict isolation between user sessions and underlying network resources. Administrators should review MongoDB configurations to disable LDAP connection pooling if it introduces unacceptable risk profiles in their specific deployment architecture, although this may impact performance scalability. Alternatively, applying vendor-provided patches that address the identity clearing logic within the pool manager is essential. It is also critical to implement rigorous monitoring of authentication logs and role assignments to detect anomalies where users appear to have permissions inconsistent with their LDAP group memberships. Regular audits of access control lists against actual user behavior can help identify instances where this flaw may have been exploited in the past, ensuring that no unauthorized privilege escalations remain undetected within the system’s operational history.