CVE-2026-73254CWE-79cross-site-scripting

CVE-2026-73254

Medium · published August 20, 2026

CVSS v3.1
5.4
EPSS
0%
Percentile
26.6
In the wild
Unconfirmed
What it is

Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can create a file with an HTML payload in its name can trigger stored cross-site scripting when a user browses a directory served with MG_ENABLE_DIRLIST. The printdirentry() path called by listdir() in src/http.c URL-encodes the href but inserts the raw filesystem filename into the HTML link text. The browser executes the injected markup in the Mongoose origin, which can expose session data or permit actions as the victim. This issue is fixed in version 7.22.

The record
Technical detail
CVSS v3.1
5.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00344 · 26.6th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-08-20T22:16Z
Affected products (1)
ProductVersionsFixed in
cesanta/mongoose< 7.227.22
References (5)
EPSS history
Timeline
  • 20 AUG 17:37Z
    Mongoose: Stored XSS via unescaped filenames in directory listing
    cvelistv5