A validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Thank you to Rich Harang for reporting this issue.
Update mcp to 1.9.4 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS affects mcp (pip). Severity is high. A validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Thank you to Rich Harang for reporting this issue.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| mcppip | <1.9.4 | 1.9.4 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
A validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Thank you to Rich Harang for reporting this issue.
Update mcp to 1.9.4 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS affects mcp (pip). Severity is high. A validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Thank you to Rich Harang for reporting this issue.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| mcppip | <1.9.4 | 1.9.4 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardReported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard