Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-hvfh-5mj3-5f3j

Chainlist has SSRF via MCP SSE and streamable-http transports that allows unauthenticated internal network access

CVSS 6.3 MediumEPSS 0.0043 · 38th percentile

Published by the GitHub Advisory Database at 25 Aug 2026, 19:21 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
chainlitPyPI>=2.4.0rc0, <2.12.02.12.0
Identifiers
GHSA-hvfh-5mj3-5f3j · CVE-2026-120492 · CVE-2026-45019 · PYSEC-2026-3811
Weakness (CWE)
CWE-918
Tags
Published
25 Aug 2026
Updated
3 Nov 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Chainlit versions from 2.4.0rc0 before 2.12.0 are vulnerable to server-side request forgery through the MCP SSE and streamable-http transports when MCP is enabled. An unauthenticated attacker who can open a session can make the server send requests to arbitrary URLs, including internal services, with attacker-chosen headers such as Authorization, though responses are not returned to the attacker. Upgrade to Chainlit 2.12.0, which fixes this issue. If you cannot upgrade, set features.mcp.enabled to false in .chainlit/config.toml, or restrict outbound network access from the host.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
6.3 Medium 4.0 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 CNA (VulnCheck)
  • CISA KEV Not listed.
  • EPSS 0.0043, the 38th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:10 UTC First seen by agentprime
  2. 31 Oct 2026, 14:10 UTC Confirmed by OSV
  3. 2 Nov 2026, 14:37 UTC Confirmed by the CVE List
  4. 2 Nov 2026, 15:22 UTC Confirmed by NVD

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.