High, CVSS 8.6npmAmendedPublished
Uni-CLI: Legacy HTTP MCP transport accepted browser-originated localhost requests
CVE-2026-58497 · GHSA-v3f4-w7r7-v3hm
- Affected
- npm @zenalexa/unicli < 0.225.2
- Fixed in
- 0.225.2· Vendor fix available
- Issue
- Impact Uni-CLI versions before 0.225.2 exposed the legacy JSON-RPC-over-HTTP MCP transport on loopback without validating browser Origin headers before routing requests. A malicious web page could send a CORS simple POST request, such as text/plain, to the local /mcp endpoint and deliver a JSON-RPC body to the dispatcher. If the user had started the local MCP HTTP transport, that page could drive tools/call requests against the user's local Uni-CLI server. The Streamable HTTP transport already enforced this browser-to-localhost boundary. The legacy stateless HTTP path did not, so the two HTTP transports had drifted. This issue is about the browser-to-localhost boundary; it does not change Uni-CLI's local-code-execution trust model. Patches Version 0.225.2 fixes the issue by moving the Origin policy into a shared guard and applying it before routing in both HTTP transports. Non-loopback browser Origins are rejected with HTTP 403 before health, OAuth, or /mcp dispatch runs. Non-browser…
Recommended action: Upgrade to 0.225.2 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.