CVE-2026-120492EPSS p12.7%

CVE-2026-120492CVE-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.

Scoring

CVSS 5.4 ()
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS0.22% probability of exploitation · percentile 12.7% · 2026-11-03T12:00:27Z
Last modified2026-11-02
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.