CVE
IBM ContextForge MCP Gateway authentication bypass in upstream credential handling
Affects IBM ContextForge MCP Gateway 1.0.0 through 1.1.0 when upstream requests use OAuth, bearer, or basic authentication. Fixed in v1.1.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Exploited
- No known exploitation
- Fix
- Fixed in v1.1.1
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Gateway uses OAuth (authorization_code or client_credentials), bearer, or basic authentication for upstream requests. Affected IBM ContextForge MCP Gateway versions 1.0.0 through 1.1.0.
- 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? →
- 16/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- 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 has an improper credential handling flaw: a request header named X-Upstream-Authorization can replace the gateway's managed upstream credential. A remote attacker with a low-privilege login can exploit this without any user action to make upstream requests under a different credential, bypassing per-user permissions and audit attribution.
Original description
IBM ContextForge MCP Gateway 1.0.0 through 1.1.0 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.
Who should check
Teams running IBM ContextForge MCP Gateway v1.0.0 through v1.1.0 with OAuth, bearer, or basic authenticated gateways; upgrade to v1.1.1.
“IBM ContextForge MCP Gateway v1.0.0 - v1.1.0”
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.1/10CVSS 8.1
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 23 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Gateway uses OAuth (authorization_code or client_credentials), bearer, or basic authentication for upstream requests. Affected IBM ContextForge MCP Gateway versions 1.0.0 through 1.1.0.Upgrade to a fixed version: v1.1.1.
Workaround: Remove the X-Upstream-Authorization request header at the reverse proxy or API gateway in front of IBM ContextForge MCP Gateway for all MCP endpoints, and restrict network access to MCP endpoints to trusted networks.
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-2026-110279 (IBM ContextForge MCP Gateway is affected by an improper authentication vulnerability), 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-2026-110279 (entry last updated 2026-11-13):
Affected:
- IBM ContextForge MCP Gateway: from 1.0.0, through 1.1.0
Fixed versions: v1.1.1.
Conditions (all must be true for the bug to be hit):
- Gateway uses OAuth (authorization_code or client_credentials), bearer, or basic authentication for upstream requests. (source: https://www.ibm.com/support/pages/node/7296490)
- Affected IBM ContextForge MCP Gateway versions 1.0.0 through 1.1.0. (source: https://www.ibm.com/support/pages/node/7296490)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, no user action.
Workaround: Remove the X-Upstream-Authorization request header at the reverse proxy or API gateway in front of IBM ContextForge MCP Gateway for all MCP endpoints, and restrict network access to MCP endpoints to trusted networks. (source: https://www.ibm.com/support/pages/node/7296490)
CISA KEV: CVE-2026-110279 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-110279 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/7296490
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-2026-110279
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-2026-110279"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- IBM ContextForge MCP Gateway
From 1.0.0 · through 1.1.0
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-2026-110279
Is CVE-2026-110279 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
What does this mean?
An authenticated user can add an X-Upstream-Authorization request header that overrides the gateway-managed upstream credential. Upstream requests then run with a different credential, which bypasses per-user permissions and audit attribution.Source: ibm.com
Which versions are affected by CVE-2026-110279?
ContextForge MCP Gateway: from 1.0.0 through 1.1.0.Source: cve.now feed data
Am I affected, and how do I check?
Versions 1.0.0 through 1.1.0 are affected when the gateway uses OAuth (authorization_code or client_credentials), bearer, or basic authentication for upstream requests. A reader can check the installed version and the upstream authentication method configured on the gateway.Source: ibm.com
How do I fix CVE-2026-110279?
Download and deploy IBM ContextForge MCP Gateway v1.1.1. Until the upgrade is done, remove the X-Upstream-Authorization request header at the reverse proxy or API gateway for all MCP endpoints and restrict network access to MCP endpoints to trusted networks.Source: ibm.com