---
id: "CVE-2026-94407"
page: "https://infrastack.ai/live/CVE-2026-94407"
kind: "vulnerability"
aliases: ["CVE-2026-94407"]
title: "IBM ContextForge MCP Gateway: regex in tool schemas can stall the gateway"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "IBM ContextForge MCP Gateway", "fixed": ["1.1.0"], "affected": ">= 1.0.0, <= 1.0.11", "ecosystem": "vendor"}]
ecosystems: []
tags: ["ai-tooling", "ibm-contextforge", "mcp", "self-hosted"]
not_affected_if: ["no-tool-registration-by-users", "version-outside-range"]
published_at: "2026-11-13T22:17:27+00:00"
first_seen_at: "2026-11-13T22:33:35+00:00"
updated_at: "2026-11-13T22:35:19+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94407", "first_seen_at": "2026-11-13T22:33:35+00:00"}, {"source": "analyst", "url": "https://www.ibm.com/support/pages/node/7296667", "first_seen_at": "2026-11-13T22:35:19+00:00", "cites": ["https://www.ibm.com/support/pages/node/7296667"]}]
exploit_sources: []
---

# IBM ContextForge MCP Gateway: regex in tool schemas can stall the gateway

Link for people: https://infrastack.ai/live/CVE-2026-94407 (this .md is for agents)

IBM ContextForge MCP Gateway 1.0.0 through 1.0.11 validates tool arguments against a JSON Schema pattern supplied at tool registration, and a crafted catastrophic-backtracking regex can make that validation consume unbounded CPU. An authenticated user with tool-registration privileges can therefore degrade or take down gateway availability.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:IBM ContextForge MCP Gateway affected >= 1.0.0, <= 1.0.11 fixed 1.1.0

## How to check

- Check the installed ContextForge version: affected if it is v1.0.0 through v1.0.11; v1.1.0 is the fixed release.
- Review which accounts can register tools or prompts, and which federated remote MCP servers you connect to: IBM says schemas from tool/prompt authors or federated remote MCP servers are evaluated without a time bound.
- IBM states no workarounds; reducing who can register tools only limits exposure.

## Fix

Upgrade IBM ContextForge MCP Gateway to v1.1.0. IBM lists no workarounds.

## Timeline

- 2026-11-13T22:33:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-94407
- 2026-11-13T22:35:19+00:00 analyst https://www.ibm.com/support/pages/node/7296667 — IBM bulletin (node/7296667) read: affected v1.0.0-v1.0.11, fix v1.1.0, no workarounds. X not checked (tier B).

## Documents

- [advisory] IBM Security Bulletin: ContextForge MCP Gateway regular expression denial of service https://www.ibm.com/support/pages/node/7296667

## From the sources

IBM ContextForge MCP Gateway 1.0.0 through 1.0.11 is potentially vulnerable to denial of service due to uncontrolled regular expression complexity (CWE-400 / ReDoS). An authenticated user with tool-registration privileges can embed catastrophically backtracking regex patterns in a tool's JSON Schema `pattern` field; when ContextForge validates arguments against that schema, the validation call may consume unbounded CPU, potentially degrading gateway availability.

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