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Security Bulletin: IBM ContextForge MCP Gateway is affected by an information exposure vulnerability

Security Bulletin


Summary

IBM ContextForge MCP Gateway can forward the identity of the calling user (such as user ID, email address, groups and teams) to upstream MCP servers when identity propagation is enabled, and allows this to be turned on or off for each registered upstream server. IBM ContextForge MCP Gateway is vulnerable to information exposure because the per-server identity propagation setting is ignored when invoking tools and reading resources, so user identity information can be sent to upstream servers that were configured not to receive it.

Vulnerability Details

CVEID:   CVE-2026-110278
DESCRIPTION:   IBM ContextForge could allow an attacker to replay identity propagation claims signatures or expose sensitive user identity information to third-party MCP servers due to static signature payloads and missing per-gateway configuration checks during tool invocation.
CWE:   CWE-294: Authentication Bypass by Capture-replay
CVSS Source:   IBM
CVSS Base score:   7.4
CVSS Vector:   (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)

Affected Products and Versions

Affected Product(s)Version(s)
IBM ContextForge MCP Gatewayv1.0.0-v1.1.0

 

Remediation/Fixes

IBM strongly recommends addressing the vulnerability now.

Product(s)Version(s) number and/or range Remediation/Fix/Instructions
IBM ContextForge MCP Gateway
v1.0.0-v1.1.0Upgrade to v1.1.1 immediately [Release notes]

 

  

Workarounds and Mitigations

IBM strongly recommends upgrading to the fixed version.
If you cannot update disable identity propagation globally (set `IDENTITY_PROPAGATION_ENABLED=false`) so that no upstream MCP server receives user identity information, and restrict access to the gateway to trusted users.

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

This vulnerability was reported to IBM by Wolfgang Kriesel.

Change History

12 Nov 2026: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
12 November 2026

Initial Publish date:
12 November 2026

UID

ibm17296489