CVE-2026-29791
Agentgateway is missing parameter sanitization in MCP to OpenAPI conversion
Impact
### 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](https://agentgateway.dev/docs/standalone/latest/mcp/connect/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](https://agentgateway.dev/docs/standalone/latest/mcp/connect/openapi/) feature ### Credits Agentgateway extends its thanks to @spacewander for the report!
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/agentgateway/agentgateway | < 0.12.0 | 0.12.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Lfprojects | Agentgateway | before 0.12.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/agentgateway/agentgateway/security/advisories/GHSA-v2x6-wwfw-r2rq
- https://github.com/advisories/GHSA-v2x6-wwfw-r2rq
- https://github.com/agentgateway/agentgateway/commit/9a5287569d892e77a8be8c3bb7bf3d7744244274
- https://nvd.nist.gov/vuln/detail/CVE-2026-29791