CVE-2026-32112CWE-79

ha-mcp has XSS via Unescaped HTML in OAuth Consent Form

Medium · published March 11, 2026

CVSS v3.1
6.8
EPSS
0%
Percentile
15.9
In the wild
Unconfirmed
What it is

ha-mcp is a Home Assistant MCP Server. Prior to 7.0.0, the ha-mcp OAuth consent form renders user-controlled parameters via Python f-strings with no HTML escaping. An attacker who can reach the OAuth endpoint and convince the server operator to follow a crafted authorization URL could execute JavaScript in the operator's browser. This affects only users running the beta OAuth mode (ha-mcp-oauth), which is not part of the standard setup and requires explicit configuration. This vulnerability is fixed in 7.0.0.

The record
Technical detail
CVSS v3.1
6.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00253 · 15.9th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-03-11T20:42Z
EPSS history
Timeline
  • 11 MAR 20:42Z
    ha-mcp has XSS via Unescaped HTML in OAuth Consent Form
    cvelistv5