CVE
IBM ContextForge MCP Gateway regex denial of service in tool schema validation
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Not reported
Do first: Apply the patch listed under Evidence.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 10/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
IBM ContextForge MCP Gateway is affected by a regular expression denial of service flaw. An attacker who can reach the gateway over the network and holds low-privilege login rights, such as the ability to register tools, can embed a catastrophically backtracking regex in a tool's JSON Schema pattern field, which may consume unbounded CPU and degrade gateway availability when arguments are validated.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Original description
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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity6.5/10CVSS 6.5
- No patch0/5No signal
What would change the score
- Would score about 65 if added to CISA KEV
- Would score about 60 if CISA's SSVC rates exploitation active
- Would score about 29 if advisories confirm default setups are exposed
What to do
Apply the patch listed under Evidence.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-94407 (IBM ContextForge MCP Gateway is affected by a regular expression denial of service), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-94407 (entry last updated 2026-11-13):
Affected:
- IBM ContextForge MCP Gateway: from 1.0.0, through 1.0.11
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-94407 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-94407 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://www.ibm.com/support/pages/node/7296667
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-94407
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-94407"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- IBM ContextForge MCP Gateway
From 1.0.0 · through 1.0.11
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Patch
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-94407
Is CVE-2026-94407 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-94407?
ContextForge MCP Gateway: from 1.0.0 through 1.0.11.Source: cve.now feed data