CVE-2026-29791
Agentgateway: Missing parameter sanitization in MCP to OpenAPI conversion
Agentgateway is an open source data plane for agentic AI connectivity within or across any agent framework or environment. Prior to version 0.12.0, when converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized. This issue has been patched in version 0.12.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Agentgateway: Missing parameter sanitization in MCP to OpenAPI conversion
Agentgateway is an open source data plane for agentic AI connectivity within or across any agent framework or environment. Prior to version 0.12.0, when converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized. This issue has been patched in version 0.12.0.
- Record
CVE-2026-29791- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2026-10070
Agentgateway is an open source data plane for agentic AI connectivity within or across any agent framework or environment. Prior to version 0.12.0, when converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized. This issue has been patched in version 0.12.0.
- Record
EUVD-2026-10070- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-v2x6-wwfw-r2rq
Agentgateway is missing parameter sanitization in MCP to OpenAPI conversion
Summary
When converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized.
Details
When using the MCP to OpenAPI feature, the proxy lacks proper sanitization of input parameters in the MCP call, allowing:
- Injection of additional path or query parameters.
- Injection of additional headers.
Impacted Versions
This vulnerability is fixed in Agentgateway v0.12.0+. Users on older versions are recommended to upgrade to v0.12.0+.
This feature only impacts usage of the MCP to OpenAPI feature
Credits
Agentgateway extends its thanks to @spacewander for the report!
- Record
GHSA-v2x6-wwfw-r2rq- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
Agentgateway is an open source data plane for agentic AI connectivity within or across any agent framework or environment. Prior to version 0.12.0, when converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized. This issue has been patched in version 0.12.0.
- Record
CVE-2026-29791- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
Agentgateway: Missing parameter sanitization in MCP to OpenAPI conversion
Agentgateway is an open source data plane for agentic AI connectivity within or across any agent framework or environment. Prior to version 0.12.0, when converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized. This issue has been patched in version 0.12.0.
- Record
CVE-2026-29791- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVGHSA-v2x6-wwfw-r2rq
Agentgateway is missing parameter sanitization in MCP to OpenAPI conversion
Summary
When converting MCP tools/call request to OpenAPI request, input path, query, and header values are not sanitized.
Details
When using the MCP to OpenAPI feature, the proxy lacks proper sanitization of input parameters in the MCP call, allowing:
- Injection of additional path or query parameters.
- Injection of additional headers.
Impacted Versions
This vulnerability is fixed in Agentgateway v0.12.0+. Users on older versions are recommended to upgrade to v0.12.0+.
This feature only impacts usage of the MCP to OpenAPI feature
Credits
Agentgateway extends its thanks to @spacewander for the report!
- Record
GHSA-v2x6-wwfw-r2rq- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/agentgateway/agentgatewayGo |
before 0.12.0 | 0.12.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-29791 is a medium vulnerability (CVSS 4.9) in Agentgateway, published March 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. Fixed in github.com/agentgateway/agentgateway 0.12.0.
References
github.com/agentgateway/agentgateway/security/advisories/GHSA-v2x6-wwfw-r2rq
nvd.nist.gov/vuln/detail/CVE-2026-29791