CVE-2026-73259

medium

Description

Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22.

References

https://github.com/cesanta/mongoose/security/advisories/GHSA-9cwm-487w-h25w

https://github.com/cesanta/mongoose/releases/tag/7.22

https://github.com/cesanta/mongoose/pull/3611

https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71

Details

Source: Mitre, NVD

Published: 2026-08-20

Updated: 2026-08-20

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.4

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00233