CVE-2025-11979: 
MongoDB vulnerability analysis and mitigation

CVE-2025-11979 is a Use After Free (CWE-416) vulnerability in MongoDB Server that allows an authorized user to crash the database server by triggering a buffer over-read condition. The vulnerability is exploited by issuing a DDL (Data Definition Language) operation concurrently with active queries under specific conditions. It affects MongoDB Server v7.0 prior to 7.0.25, v8.0 prior to 8.0.15, and version 8.2.0. The CVE was published on October 20, 2025, with NVD initial analysis completed December 4, 2025. The CVSS v3.1 base score is 6.5 (Medium) per NVD, and 5.3 (Medium) per MongoDB, Inc. (MongoDB Jira, Red Hat Advisory).

The root cause is classified as CWE-416 (Use After Free), manifesting as a buffer over-read when a DDL operation (e.g., schema modification or index creation) is issued concurrently with in-flight queries under specific timing conditions. This race condition can cause the server to read memory beyond the intended buffer boundary, leading to a crash. The attack vector is network-based and requires low-privilege authenticated access with no user interaction, though MongoDB's own CNA scoring reflects higher attack complexity (AC:H), suggesting the race condition is not trivially reproducible. No public proof-of-concept code has been identified (MongoDB Jira, Red Hat Advisory).

Successful exploitation results in a denial of service through a MongoDB server crash, impacting availability with no effect on confidentiality or integrity. Any application or service dependent on the affected MongoDB instance would experience an outage for the duration of the crash and recovery period. The impact is limited to availability (HIGH) and does not enable data exfiltration, privilege escalation, or lateral movement (MongoDB Jira).

There is no evidence of active in-the-wild exploitation or publicly available proof-of-concept code as of the time of reporting. The vulnerability requires authenticated (low-privilege) access, reducing the attack surface compared to unauthenticated vulnerabilities. The EPSS score is approximately 0.04%, indicating a very low probability of exploitation in the near term. CVE-2025-11979 is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog (Red Hat Advisory).

MongoDB has released patched versions addressing this vulnerability: upgrade to MongoDB Server 7.0.25 or later for the 7.0.x series, and 8.0.15 or later for the 8.0.x series. MongoDB Server 8.2.0 is also affected; users should upgrade to a fixed release. As interim mitigations, administrators should implement strict access controls to limit which users can issue DDL operations, monitor for unusual concurrent DDL and query activity, and use network segmentation to restrict database access to trusted clients only (MongoDB Jira, Red Hat Advisory).