{"action":"Upgrade mcp to 0.23.0 or later.","affected":[{"fixed":"0.23.0","introduced":"0"}],"component":"mcp","cve_ids":["CVE-2026-63119"],"ecosystem":"RubyGems","epss":0.00188,"exploited":false,"fixed_versions":["0.23.0"],"ghsa_id":"GHSA-7683-3w9x-ch42","id":"tcs_01M5KEHKASW5EKXCG0SED59B4V","modified_at":"2026-07-30T14:45:28.029711933Z","published_at":"2026-07-30T14:41:58Z","references":["https://osv.dev/vulnerability/GHSA-7683-3w9x-ch42","https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-7683-3w9x-ch42","https://nvd.nist.gov/vuln/detail/CVE-2026-63119","https://github.com/modelcontextprotocol/ruby-sdk/commit/267b8fa6285453525c81ce43db6b7dcd7a8a8c2f","https://github.com/modelcontextprotocol/ruby-sdk","https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0"],"severity":{"label":"medium","score":6.2},"sources":[{"source":"osv","source_id":"GHSA-7683-3w9x-ch42","url":"https://osv.dev/vulnerability/GHSA-7683-3w9x-ch42"}],"summary":"MCP Ruby SDK: Unbounded line buffer in stdio transports leads to memory exhaustion (DoS)"}