Security Bulletin
Summary
IBM ContextForge MCP Gateway forwards client requests to upstream MCP servers and can hold the upstream credential itself, for example a stored per-user OAuth token, a client-credentials token, or bearer, basic or custom authentication headers configured on a gateway. IBM ContextForge MCP Gateway is vulnerable to improper authentication (credential override) because the X-Upstream-Authorization request header is always renamed to Authorization for upstream requests, so an authenticated user could replace the gateway-managed upstream credential with a different credential.
Vulnerability Details
CVEID: CVE-2026-110279
DESCRIPTION: IBM ContextForge is vulnerable to improper credential handling because the X-Upstream-Authorization request header can override the gateway-managed upstream credential for OAuth (authorization_code and client_credentials), bearer and basic authenticated gateways, which could allow an authenticated user to cause upstream requests to be made with a different credential and bypass per-user permission and audit attribution.
CWE: CWE-287: Improper Authentication
CVSS Source: IBM
CVSS Base score: 8.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N)
Affected Products and Versions
Affected Products/Versions guidance:
| Affected Product(s) | Version(s) |
| IBM ContextForge MCP Gateway | v1.0.0 - 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 | 2.0 | Download and deploy v1.1.1 [Release notes v1.1.1] |
Workarounds and Mitigations
Get Notified about Future Security Bulletins
References
- Fixing PR: https://github.com/IBM/mcp-context-forge/pull/7341
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
ibm17296490