CVE-2025-66419 is a race condition vulnerability (CWE-362) found in MaxKB, an open-source AI assistant designed for enterprise environments. The flaw exists in versions 2.3.1 and earlier within the tool module, where concurrent execution of shared resources is improperly synchronized. This improper synchronization allows an attacker with low privileges and network access to trigger a race condition that escapes the sandbox environment, thereby escalating their privileges within the system. The vulnerability does not require user interaction, increasing its exploitability. The sandbox escape can lead to unauthorized access to sensitive data, modification or deletion of critical information, and disruption of service availability. The vulnerability has a CVSS v3.1 score of 8.8, reflecting its high impact on confidentiality, integrity, and availability. The issue was publicly disclosed on December 11, 2025, and fixed in MaxKB version 2.4.0. Although no exploits are currently known in the wild, the nature of the vulnerability and its ease of exploitation make it a significant threat to organizations relying on MaxKB for AI assistance in enterprise workflows.

For European organizations, this vulnerability poses a serious risk due to the potential for attackers to gain elevated privileges and bypass sandbox restrictions, which can lead to unauthorized data access, data tampering, and service disruption. Enterprises using MaxKB in sectors such as finance, healthcare, government, and critical infrastructure could face severe operational and reputational damage if exploited. The compromise of AI assistant tools may also expose sensitive intellectual property and personal data, triggering regulatory compliance issues under GDPR. The network-exploitable nature of the flaw means attackers can launch attacks remotely, increasing the threat surface. The lack of required user interaction further heightens the risk of automated or large-scale exploitation attempts. Organizations with complex concurrent processing environments may find it challenging to detect exploitation attempts, increasing the likelihood of prolonged undetected breaches.

1. Immediate upgrade to MaxKB version 2.4.0 or later to apply the official patch fixing the race condition. 2. Conduct a thorough audit of all systems running vulnerable MaxKB versions to identify and isolate affected instances. 3. Implement strict network segmentation and access controls to limit exposure of MaxKB services to trusted internal networks only. 4. Monitor logs and system behavior for unusual concurrent execution patterns or privilege escalation attempts. 5. Employ runtime application self-protection (RASP) or endpoint detection and response (EDR) tools capable of detecting race condition exploitation techniques. 6. Review and harden sandbox configurations and concurrency controls within MaxKB deployments. 7. Educate development and operations teams on secure concurrent programming practices to prevent similar issues in custom integrations or extensions. 8. Prepare incident response plans specifically addressing potential AI assistant compromise scenarios.