CVE-2026-73259 — MEDIUM (5.4)

Vulnerability 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.

CVSS Score

5.4

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

LOW

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-79

References

FAQ

What is CVE-2026-73259?

CVE-2026-73259 is a vulnerability with a CVSS score of 5.4 (MEDIUM). 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 ...

How severe is CVE-2026-73259?

CVE-2026-73259 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-73259?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.