Intel

AIKIDO-2026-701225

cesanta.mongoose is vulnerable to Denial of Service (DoS)

Denial of Service (DoS)CVE-2026-52054 Published Aug 14, 2026

65

Medium Risk

This Affects:

C++cesanta.mongoose
7.21 - 7.21
Fixed in 7.22
Are you affected? Scan for Free

TL;DR

find_opt in the built-in TCP/IP PPP option parser (src/l2_ppp.c) walks peer-supplied IPCP/IPV6CP options using each option's self-declared length byte, but never rejects a length below the 2-byte minimum. An option whose length byte is 0 advances the cursor by zero, so the loop never exits and the single-threaded event loop hangs. A network-adjacent PPP or PPPoE peer can permanently deny service with one crafted configuration packet. The fix rejects option lengths below 2 before advancing the parser.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and build Mongoose with the built-in TCP/IP stack (MG_ENABLE_TCPIP) using a PPP or PPPoE Layer-2 driver. Application-only users over host sockets are not affected.

Background info

cesanta.mongoose is vulnerable to Denial of Service (DoS) in versions 7.21 - 7.21.

How to fix this

Upgrade the mongoose library to the patch version.