// CVE

CVE-2026-42271

High 8.7 Exploited (KEV)

BerriAI LiteLLM

8.7CVSS
83%EPSS
YesCISA KEV

Summary

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it — POST /mcp-rest/test/connection and POST /mcp…

Published: 2026-05-08 · In KEV since: 2026-06-08

Analysis

🔴 Critical — actively exploited

How it's exploited: Exploitable over the network (internet-reachable), with low privileges, no user interaction, and with low complexity.

Impact: Full compromise (confidentiality, integrity and availability).

Status: Active exploitation confirmed by CISA (KEV).

How to defend:
  • Patch now: it is in CISA's actively-exploited catalog (KEV), with a deadline.
  • Reduce exposure: keep it off the internet; firewall, VPN or network segmentation.
  • Detect: turn this CVE into detection rules.

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/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

The vector encodes how it's exploited (translated above, in the analysis). Break it down in the CVSS tool →

🔗 NVD record CISA KEV 🌉 CVE → detection 🎯 Am I exposed? ⚖️ Prioritize patch

← Back to the Threat Radar

Sources: CISA KEV · EPSS · FIRST.org · NVD. Analysis derived from the CVSS vector and exploitation status (no AI). Informational; always verify against the vendor's official advisory.