CVE-2026-96744: MongoDB Laravel Cache Lock Auth Bypass

CVE-2026-96744 Overview

CVE-2026-96744 is a NoSQL injection vulnerability in the MongoDB integration for Laravel. The flaw resides in the cache lock implementation, where a caller-supplied lock owner value is evaluated as an aggregation expression rather than as a literal value. An authenticated attacker who can influence the owner value during lock acquisition or restoration may take over or prematurely expire a lock held by another process. This can lead to duplicated or conflicting operations across application workflows that depend on cache locks for mutual exclusion. The weakness is tracked under CWE-943: Improper Neutralization of Special Elements in Data Query Logic.

Critical Impact

Authenticated attackers can hijack or expire cache locks owned by other processes, enabling duplicate execution of critical operations and integrity violations.

Affected Products

• mongodb/laravel-mongodb package versions prior to 5.11.0
• Laravel applications using the MongoDB cache driver with lock functionality
• Downstream applications that pass user-influenced values into cache lock owner parameters

Discovery Timeline

• 2026-09-24 - CVE-2026-96744 published to the National Vulnerability Database
• 2026-09-24 - Last updated in NVD database

Technical Details for CVE-2026-96744

Vulnerability Analysis

The vulnerability affects the cache lock implementation in the MongoDB integration for Laravel. Laravel cache locks use an owner value to track which process holds a lock. The MongoDB driver passed this owner value into query logic without proper neutralization. As a result, structured input could be interpreted as an aggregation expression instead of a literal string comparison.

An authenticated user capable of controlling the owner value can craft input that matches locks held by other owners. This enables the attacker to release, overwrite, or extend arbitrary locks. Because Laravel cache locks commonly guard job dispatching, scheduled tasks, and transactional workflows, lock takeover can cause the same operation to run multiple times concurrently or allow an in-progress critical section to be interrupted.

The impact is primarily on integrity. Confidentiality and availability effects are limited, but duplicated operations in payment, inventory, or messaging flows can produce significant downstream consequences.

Root Cause

The root cause is improper neutralization of special elements in data query logic (CWE-943). The lock acquisition and restoration code treated the owner parameter as a query fragment rather than a literal value. MongoDB operators such as $gt, $ne, or aggregation expressions embedded in the owner field were evaluated server-side.

Attack Vector

Exploitation requires network access and low-privilege authenticated access to an application endpoint that forwards user input into the cache lock owner value. The attacker submits a crafted owner value structured as a MongoDB operator or aggregation expression. When the application calls lock acquisition or restoration, the driver evaluates the attacker's structure against stored lock documents and matches locks owned by other processes.

No user interaction is required beyond the initial request. The vulnerability manifests entirely server-side within the MongoDB query pipeline. Full technical details are available in the upstream fix at GitHub Pull Request #3579.

Detection Methods for CVE-2026-96744

Indicators of Compromise

• Cache lock documents in MongoDB with unexpected or structured owner field values containing operator syntax such as $gt, $ne, or $where
• Application logs showing duplicate execution of jobs or tasks that are guarded by Cache::lock() calls
• Unexpected lock release events where the releasing owner does not match the acquiring owner in audit trails

Detection Strategies

• Audit all application code paths that pass user-controlled or request-derived input into the second argument of Cache::lock($key, $seconds, $owner) or restoreLock()
• Inspect MongoDB query logs for lock collection operations containing document structures in the owner field rather than scalar strings
• Correlate web request logs with lock release events to identify requests that trigger lock state transitions for keys the user should not control

Monitoring Recommendations

• Enable MongoDB query profiling on the cache collection to capture queries containing operator expressions in equality predicates
• Monitor the frequency of lock acquisition, release, and restoration events per application endpoint for anomalies
• Alert on job executions that complete more than once within a lock TTL window, indicating potential lock bypass

How to Mitigate CVE-2026-96744

Immediate Actions Required

• Upgrade mongodb/laravel-mongodb to version 5.11.0 or later, which contains the patch from Pull Request #3579
• Review all application code that uses cache locks and remove any paths where user input reaches the lock owner parameter
• Rotate or invalidate existing cache lock documents in MongoDB to clear any attacker-planted structured owner values

Patch Information

The fix is included in mongodb/laravel-mongodb version 5.11.0. Release notes are available at GitHub Release v5.11.0. The patch ensures the owner value is treated as a literal string during lock operations rather than being evaluated as a MongoDB query or aggregation expression.

Workarounds

• Enforce server-side generation of lock owner values using cryptographically random identifiers rather than accepting any client-supplied value
• Validate that owner parameters passed to lock operations are strings matching an expected format such as a UUID before invoking lock methods
• Restrict authenticated access to endpoints that interact with cache locks until the package upgrade is completed

# Upgrade the MongoDB Laravel integration to the patched release
composer require mongodb/laravel-mongodb:^5.11.0
composer update mongodb/laravel-mongodb
php artisan cache:clear