Cyber Resilience

CVE-2026-32112

XSS in Homeassistant-Ai Home Assistant Mcp Server ≤ 7.0.0

Published
11 March 2026
Modified
17 March 2026
Patch / advisory
CVSS Score v3.1 6.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0018 8th percentile
Risk Priority 42 floored blend · peak EPSS

Summary

CVE-2026-32112 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Homeassistant-Ai Home Assistant Mcp Server. Its CVSS base score is 6.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Other ATLAS/OWASP Terms risk domain.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

AI Security AnalysisAI

AI Category
AI Agent Protocols and Integrations
Risk Domain
Other ATLAS/OWASP Terms
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: mcp

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

CWE-79 XSS in public-facing OAuth endpoint directly enables exploitation of the web application (T1190).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-5564Shared CWE-79
CVE-2023-46134Shared CWE-79
CVE-2023-46378Shared CWE-79
CVE-2023-6568Shared CWE-79
CVE-2023-6649Shared CWE-79
CVE-2023-6465Shared CWE-79
CVE-2023-6945Shared CWE-79
CVE-2023-49490Shared CWE-79
CVE-2023-6462Shared CWE-79
CVE-2023-46492Shared CWE-79

Affected Assets

homeassistant-ai
home assistant mcp server
≤ 7.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-15 Information Output Filtering
  • SI-10 Information Input Validation
  • SI-3 Malicious Code Protection
Detect
Catch it (NIST detect / respond)
  • SI-3 Malicious Code Protection
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires filtering of information outputs to remove or encode untrusted content before rendering, preventing the unsanitized f-string injection into the OAuth consent form HTML.

prevent

Requires validation of all input data (here, user-controlled OAuth parameters) to reject or sanitize dangerous content such as script tags before it reaches the template renderer.

preventdetect

Deploys malicious-code protections that can block or alert on execution of injected JavaScript payloads delivered via the crafted authorization URL.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

none

Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.

References