CVE-2017-2921: Cesanta Mongoose

Critical severity, CVSS 9.8. EPSS: 2.4% chance of exploitation in the next 30 days.

An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8. A specially crafted websocket packet can cause an integer overflow, leading to a heap buffer overflow and resulting in denial of service and potential remote code execution. An attacker needs to send a specially crafted websocket packet over network to trigger this vulnerability.

Affected products

• Cesanta Mongoose: version 6.8 only

Published 2017-11-07. Last modified 2026-06-17.