Intel

AIKIDO-2026-975500

cesanta.mongoose is vulnerable to Path Traversal

Path TraversalCVE-2026-73255 Published Aug 13, 2026

65

Medium Risk

This Affects:

C++cesanta.mongoose
7.1.0 - 7.21.0
Fixed in 7.22.0
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TL;DR

When Server-Side Includes are enabled, the include directive handler concatenates the directive path into a filesystem path without sanitizing ../ sequences. Content that reaches an .shtml file can therefore read arbitrary files readable by the process, such as system password files, configuration, or private keys. Exploitation requires control over included content but no elevated privileges. The fix validates include paths before opening them.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and you enable Server-Side Includes (MG_ENABLE_SSI) and serve .shtml content that untrusted input can influence.

Background info

cesanta.mongoose is vulnerable to Path Traversal in versions 7.1.0 - 7.21.0.

How to fix this

Upgrade the cesanta.mongoose library to the patch version.