Most recent entries from all https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Tue, 29 Sep 2026 23:44:17 +0000 CVE-2025-53366 — MCP SDK Vulnerable to FastMCP Server Validation Error, Leading to Denial of Service https://vulnerability.circl.lu/vuln/cve-2025-53366 <p><strong>Affected:</strong> modelcontextprotocol python-sdk</p> <p>The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.9.4, 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. Version 1.9.4 contains a patch for the issue.</p> <p><strong>Affected:</strong> modelcontextprotocol python-sdk</p> <p>The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.9.4, 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. Version 1.9.4 contains a patch for the issue.</p> https://vulnerability.circl.lu/vuln/cve-2025-53366 GHSA-3qhf-m339-9g5v — MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS https://vulnerability.circl.lu/vuln/ghsa-3qhf-m339-9g5v <p><strong>Affected:</strong> PyPI: mcp</p> <p>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.</p> <p>Thank you to Rich Harang for reporting this issue.</p> <p><strong>Affected:</strong> PyPI: mcp</p> <p>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.</p> <p>Thank you to Rich Harang for reporting this issue.</p> https://vulnerability.circl.lu/vuln/ghsa-3qhf-m339-9g5v PYSEC-2026-1616 — MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS https://vulnerability.circl.lu/vuln/pysec-2026-1616 <p><strong>Affected:</strong> PyPI: mcp</p> <p>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.</p> <p>Thank you to Rich Harang for reporting this issue.</p> <p><strong>Affected:</strong> PyPI: mcp</p> <p>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.</p> <p>Thank you to Rich Harang for reporting this issue.</p> https://vulnerability.circl.lu/vuln/pysec-2026-1616