{"action":"Upgrade mcp to 0.23.0 or later.","affected":[{"fixed":"0.23.0","introduced":"0"}],"component":"mcp","cve_ids":["CVE-2026-67430"],"ecosystem":"RubyGems","epss":0.00367,"exploited":false,"fixed_versions":["0.23.0"],"ghsa_id":"GHSA-52jp-gj8w-j6xh","id":"tcs_01M5KEGT2HKGVHYPW6GFKE9ZB3","modified_at":"2026-07-30T15:00:31.152089988Z","published_at":"2026-07-30T14:43:29Z","references":["https://osv.dev/vulnerability/GHSA-52jp-gj8w-j6xh","https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-52jp-gj8w-j6xh","https://nvd.nist.gov/vuln/detail/CVE-2026-67430","https://github.com/modelcontextprotocol/ruby-sdk/commit/afb968c468c178c4d3294b423fcce250621692f4","https://github.com/modelcontextprotocol/ruby-sdk","https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0"],"severity":{"label":"medium","score":5.3},"sources":[{"source":"osv","source_id":"GHSA-52jp-gj8w-j6xh","url":"https://osv.dev/vulnerability/GHSA-52jp-gj8w-j6xh"}],"summary":"MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood"}