IBM ContextForge MCP Gateway is affected by security filter bypass via nested payload structures
Summary
| CVE | CVE-2026-11918 |
|---|---|
| State | PUBLISHED |
| Assigner | ibm |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-15 18:17:12 UTC |
| Updated | 2026-09-20 01:16:27 UTC |
| Description | IBM ContextForge MCP Gateway <= v1.0.4 IBM mcp-context-forge could allow an authenticated user to bypass protection mechanisms due to incomplete recursive inspection of nested payload content. |
Risk And Classification
Primary CVSS: v3.1 5.4 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS: 0.002720000 probability, percentile 0.196910000 (date 2026-09-16)
Problem Types: CWE-184 | CWE-184 CWE-184 Incomplete List of Disallowed Inputs
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | CVSS | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | IBM | ContextForge MCP Gateway | affected <= v1.0.4 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.ibm.com/support/pages/node/7285720 | [email protected] | www.ibm.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
Solutions
CNA: | Product | Affected Version(s) | Fix Version | Instructions | |---|---|---|---| | | <=1.0.4 | 1.0.5 | Upgrade to v1.0.5 or later. . | IBM strongly recommends addressing the vulnerability now. Product(s)Version(s) number and/or range Remediation/Fix/InstructionsIBM ContextForge MCP Gateway<=1.0.4 v1.0.5 or later See [release notes]( https://github.com/IBM/mcp-context-forge/releases/tag/v1.0.5) https://github.com/IBM/mcp-context-forge/releases/tag/v1.0.5%29 Note: <Component A / B names> are bundled with <Product profile name> to provide <feature / function description>
Workarounds
CNA: There is no workaround that fully prevents the bypass while keeping the affected plugins active. Operators may disable `regex_filter` and `deny_filter` in `plugins/config.yaml` to prevent exploitation, at the cost of losing the filtering controls those plugins provide. IBM strongly recommends upgrading to v1.0.5 or higher, which replaces the top-level-only scan loops with a recursive walker in both plugins.