CVE-2026-82053: MongoDB LDAP Privilege Escalation Flaw

CVE-2026-82053 Overview

CVE-2026-82053 is an authorization flaw in MongoDB's Lightweight Directory Access Protocol (LDAP) integration. Pooled LDAP connections can retain stale authentication identities after a user authenticates under certain configurations. Subsequent authorization queries then execute under an unintended LDAP identity rather than the expected one. This mismatch can cause MongoDB to assign roles based on the wrong directory entry. An authenticated user may acquire elevated privileges that the deployment's authorization policy never intended to grant. The issue is tracked under CWE-863: Incorrect Authorization.

Critical Impact
Authenticated MongoDB users may receive elevated roles derived from another LDAP identity, breaking the deployment's access control model.

Affected Products

MongoDB Server deployments using LDAP for authorization
Configurations that rely on pooled LDAP connections for directory lookups
Refer to MongoDB Jira Issue SERVER-130785 for version-level details

Discovery Timeline

2026-09-08 - CVE-2026-82053 published to the National Vulnerability Database (NVD)
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-82053

Vulnerability Analysis

MongoDB supports LDAP authorization by mapping authenticated users to roles derived from LDAP group membership. To reduce directory lookup latency, the server pools LDAP connections and reuses them across sessions. Under specific configurations, a pooled connection can retain the authenticated identity from a prior operation. When MongoDB reuses that connection for a new authorization query, the directory server evaluates the query in the context of the wrong bound identity.

The authorization decision therefore depends on the access control state of a stale identity in the LDAP tree rather than the current user. Depending on directory ACLs, the server may read group memberships or attributes that the intended user cannot access. MongoDB then assigns roles based on that incorrect result.

Root Cause

The root cause is improper binding of authentication state to pooled LDAP connections. Connection reuse does not reset or rebind the identity before executing authorization queries. This is a classic incorrect authorization pattern captured by CWE-863, where the access control decision uses inputs from the wrong security context.

Attack Vector

Exploitation requires an authenticated user with valid credentials against the MongoDB deployment. The attack is network-based, requires low privileges, and depends on the LDAP pool holding a stale, higher-privileged identity at the moment authorization runs. When conditions align, the attacker's session inherits role mappings derived from that other identity, resulting in vertical privilege escalation within MongoDB.

No public proof-of-concept, exploit code, or CISA Known Exploited Vulnerabilities (KEV) listing is associated with this CVE at publication time. Technical details are documented in MongoDB Jira Issue SERVER-130785.

Detection Methods for CVE-2026-82053

Indicators of Compromise

Unexpected role assignments visible in db.getUser() output that do not match the user's LDAP group membership
MongoDB audit log entries showing authorization results inconsistent with the authenticating principal
LDAP server logs where bind identities do not correlate with the MongoDB session that triggered the query
Sudden appearance of privileged operations from accounts that historically held only read-level roles

Detection Strategies

Enable MongoDB auditing and record authCheck and authenticate events, then correlate the authenticating user with the roles resolved for each session
Compare LDAP group membership snapshots against the roles MongoDB grants to the same users over time
Alert on privilege escalation transitions where a user gains administrative roles without a corresponding LDAP directory change

Monitoring Recommendations

Forward MongoDB audit logs and LDAP directory logs into a centralized analytics platform for cross-source correlation
Track LDAP connection pool metrics, including bind churn and reuse counts, to identify anomalous reuse patterns
Baseline the role assignments granted per user and alert on deviations that indicate authorization drift

How to Mitigate CVE-2026-82053

Immediate Actions Required

Review MongoDB Jira Issue SERVER-130785 and apply the fixed MongoDB Server build for your release train
Audit all users authenticated through LDAP and validate their current role assignments against expected LDAP group membership
Rotate credentials for any account observed with unexpected elevated privileges during the exposure window

Patch Information

MongoDB tracks the fix under SERVER-130785. Consult the linked issue and MongoDB release notes for the specific patched versions applicable to your deployment. Apply the vendor-supplied patch to restore correct binding of authentication identity to pooled LDAP connections.

Workarounds

Disable LDAP connection pooling for authorization queries where the configuration option is available, accepting the added latency
Restrict LDAP authorization to a dedicated service account with narrowly scoped directory ACLs so that stale identities cannot resolve broader group membership
Enforce least privilege in the LDAP directory so that no single identity in the pool holds broad read access to sensitive group attributes

bash

# Configuration example: audit LDAP-authorized role assignments
mongosh --host <mongo-host> --tls \
  --authenticationMechanism PLAIN \
  --authenticationDatabase '$external' \
  -u '<admin-user>' -p \
  --eval 'db.getSiblingDB("admin").system.users.find({}, {user:1, roles:1, _id:0}).forEach(printjson)'