Dashboard / CVE-2026-120492

CVE-2026-120492

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 73/100
Published: 2026-11-02 Modified: 2026-11-07 First seen: 2026-11-02 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: X
AT: Present
VC: None
VI: None
VA: None

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.

Weakness Classification (1)

Affected Software (2)

VendorProductVersion
Chainlit Chainlit 2.12.0
Chainlit Chainlit 2.12.0

References & Advisories (4)

Bug Bounty Relevance

73 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.22%
Raw Score 0.002210
Percentile 12.8%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00221
2026-11-12
0.00221
2026-11-10
0.00221
2026-11-09
0.00221
2026-11-08
0.00221
2026-11-07
0.00221
2026-11-06
0.00221
2026-11-05
0.00221
2026-11-04
0.00221
2026-11-03
0.00221

Intelligence Sources

mitre ref →
nvd ref →

External Links