Cross-site scripting in Mongoose - CVE-2026-73259
Published: August 12, 2026 / Updated: August 13, 2026
Vulnerability identifier: #VU142185
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-73259
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary JavaScript in the victim\'s browser context.
The vulnerability exists due to cross-site scripting in the listdir() directory listing renderer when rendering a URL-decoded request URI into the <title> and <h1> elements. A remote attacker can send a specially crafted link to execute arbitrary JavaScript in the victim\'s browser context.
User interaction is required to open a crafted link, and the issue is exposed only when directory listing is enabled with MG_ENABLE_DIRLIST.
Affected software
Mongoose
How to mitigate CVE-2026-73259
Install security update from vendor's website.
Mongoose - update to 7.22