CVE-2026-62863

Summary

MoLing's SSE mode exposes unauthenticated /sse and /message endpoints with permissive CORS, allowing any malicious website to hijack a victim's session via cross-origin EventSource to steal the sessionId and issue unauthorized MCP tool calls.

Exploitability

Exploitation requires the victim to visit a malicious webpage while MoLing runs in SSE mode; no special privileges or user interaction beyond visiting the page is needed.

Blast radius

Attackers can execute arbitrary local commands, read/write files, or perform other actions based on the configured MCP tools, leading to full system compromise depending on tool permissions.

Detection

Defenders may observe unexpected cross-origin EventSource connections to /sse from browsers, or repeated /message requests using unfamiliar session IDs not tied to known user sessions; however, no reliable host or network indicator is derivable from the published description.

Prioritized remediation

Upgrade to MoLing version 0.5.0 or later, which fixes the authentication and CORS issues.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.