Is CVE-2026-120492 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-120492?

CVE-2026-120492 has a CVSS v3 severity of MEDIUM (5.4).

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CVE-2026-120492

Description

Chainlit 2.12.0 contains a server-side request forgery vulnerability that allows unauthenticated attackers to bypass path-scoped MCP allowed_urls entries because validate_mcp_url does not reject the semicolon character. Attackers can submit MCP URLs with '..;' segments to the /mcp endpoint, causing requests to paths outside the operator's grant on origins that strip semicolon path parameters.