Cross-Site Scripting (XSS) in ha-mcp (CVE-2026-32112)
Summary
Cross-site scripting in ha-mcp (CVE-2026-32112). Confidential information can be exposed externally. Exploitable via consent_form.py. Mitigation: upgrade to 7.0.0 or later.
Original description
The description as published by the source.
Summary
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.
Details
Unescaped f-string rendering
consent_form.py builds HTML using Python f-strings. No call to html.escape() exists anywhere in the file. The following values are rendered unescaped:
client_name/client_id— in HTML element context (lines 299, 303)client_id,redirect_uri,state— in HTML attribute context (lines 310–312), where a"character breaks out ofvalue=""error_message,error,error_description— in error display paths (lines 36–40, 496–497)
An attacker can register a client with a malicious client_name via the /register (DCR) endpoint, which accepts client_name without sanitization. If the server operator then visits a crafted authorization URL for that client, the payload executes in their browser.
Open Dynamic Client Registration
DCR is enabled by default with no initial access token required. This is intentional: Claude.ai and ChatGPT must self-register on first use, which is the standard MCP OAuth flow (RFC 7591). Requiring a pre-shared token would break those integrations…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-32112 has been found in ha-mcp.
Attackers can target a specific entry point like consent_form.py over the network to misuse the product.
Confidential information can be exposed externally.
What to do: upgrade ha-mcp to 7.0.0 or later.
If unsure, ask your IT team or search "ha-mcp CVE-2026-32112" on the vendor's site.
CVE-2026-32112 (ha-mcp) — CWE-79
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: consent_form.py / client_name / client_id / redirect_uri
Patched: 7.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in ha-mcp. Attackers reach the vulnerable code path via consent_form.py without authentication.
Check the vendor advisory for the affected versions of ha-mcp. Attack surface: consent_form.py / client_name / client_id / redirect_uri.
Severity: ?. Confidential information can be exposed externally.
Update to 7.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'ha-mcp' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'ha-mcp' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
ha-mcpを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade ha-mcp to 7.0.0ステージング環境で 7.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com