CVE-2025-11979 is a use-after-free vulnerability (CWE-416) identified in MongoDB Server versions prior to 7.0.25, 8.0.15, and including 8.2.0. The flaw arises when an authorized user issues Data Definition Language (DDL) operations concurrently with ongoing queries, which under certain conditions causes a buffer over-read leading to a server crash. This vulnerability affects the availability of the MongoDB service but does not compromise confidentiality or integrity. The attack vector is network-based, requiring low privileges (authorized user) but no user interaction. The attack complexity is high, indicating that exploitation requires specific timing or conditions to trigger the vulnerability. The CVSS v3.1 base score is 5.3 (medium severity), reflecting the impact on availability without confidentiality or integrity loss. No public exploits are known, and no patches are currently linked, though MongoDB Inc. is expected to release fixes. The vulnerability could be exploited to cause denial of service (DoS), disrupting database availability and potentially impacting dependent applications and services. Given MongoDB's widespread use in enterprise environments, especially in sectors requiring high availability and data integrity, this vulnerability poses a moderate operational risk.

For European organizations, the primary impact is on availability, as exploitation results in a server crash causing denial of service. This can disrupt critical business applications relying on MongoDB databases, including financial services, healthcare, e-commerce, and government systems. The requirement for an authorized user to exploit the vulnerability limits the attack surface but insider threats or compromised credentials could be leveraged. The high attack complexity reduces the likelihood of widespread exploitation but targeted attacks against high-value systems remain a concern. Organizations with high transaction volumes or real-time data processing may experience significant operational disruptions. Additionally, service outages could lead to reputational damage and regulatory scrutiny, especially under GDPR mandates for service continuity and data protection. The lack of confidentiality or integrity impact reduces risks related to data breaches but availability interruptions alone can have severe business consequences.

1. Upgrade MongoDB Server to versions 7.0.25, 8.0.15, or later once patches are released by MongoDB Inc. Monitor official channels for patch availability. 2. Until patches are applied, restrict DDL operations during periods of high query activity or implement operational controls to avoid concurrent DDL and query execution. 3. Enforce strict access controls and monitor authorized user activities to detect unusual or suspicious DDL commands that could trigger the vulnerability. 4. Implement robust credential management and insider threat detection to minimize risk from authorized users exploiting this flaw. 5. Employ database clustering and failover mechanisms to maintain availability in case of crashes. 6. Regularly audit MongoDB logs for signs of crashes or abnormal behavior related to DDL and query concurrency. 7. Consider network segmentation and limiting database access to trusted hosts to reduce exposure. 8. Prepare incident response plans for potential denial of service scenarios affecting MongoDB infrastructure.