A critical integer overflow vulnerability in Mongoose versions 7.5 through 7.17 allows unauthenticated remote attackers to cause application crashes, potentially leading to buffer overflows.

The vulnerability exists in the WebSocket component of the Mongoose library. An unauthenticated attacker can trigger an integer overflow by sending a specially crafted WebSocket request, leading to service disruption or potential memory corruption if integrated improperly by downstream applications.

The vulnerability carries a CVSS score of 7.5, indicating a high severity due to the lack of required authentication and the ease of exploitation. Successful exploitation results in a denial of service, which can cause significant operational downtime and business disruption. Furthermore, the risk of escalation to buffer overflow conditions in specific implementations increases the potential for unauthorized code execution or system compromise.

Immediate Action: Update the Mongoose library to a version beyond 7.17, as specified in the vendor security advisory, or apply the fix provided in the upstream repository pull request #3131.

Proactive Monitoring: Monitor application logs for anomalous WebSocket traffic or recurring service crashes, which may indicate exploitation attempts.

Compensating Controls: Deploy a Web Application Firewall (WAF) with rules configured to inspect and filter malformed or oversized WebSocket frames to prevent malicious payloads from reaching the Mongoose component.

Public Exploit Available: Yes, a public proof-of-concept exists as referenced in the linked GitHub repository cainiao159357/CVE-2025-51495.

Given the availability of a proof-of-concept and the ease of triggering this vulnerability, immediate patching is required. Organizations utilizing Mongoose in their network-facing applications must prioritize updating the library to a secure version to mitigate the risk of denial of service and potential memory-based attacks.