{"answers":{"affected":"2 open source packages ship an affected version, including mcp.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67430 exists.","fix":"Upgrade mcp to 0.23.0 or later.","what":"CVE-2026-67430 is a medium-severity denial of service vulnerability in modelcontextprotocol ruby-sdk, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-67430 and fix it if it is affected.\n\nWhat it is: CVE-2026-67430 is a medium-severity denial of service vulnerability in modelcontextprotocol ruby-sdk, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67430 exists.\n\nAffected packages and fixed versions:\n- mcp (RubyGems): affected all versions; fixed in 0.23.0\n- mcp (RubyGems): affected all versions; fixed in 0.23.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-67430/ (Markdown: https://insights.sbomify.com/CVE-2026-67430/index.md)","id":"CVE-2026-67430","markdown":"https://insights.sbomify.com/CVE-2026-67430/index.md","name":"CVE-2026-67430","record":{"aliases":["GHSA-52jp-gj8w-j6xh"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Ruby MCP SDK","requires_auth":"none","summary":"Attackers can exhaust server memory by flooding initialize requests due to unbounded session retention in the MCP Ruby SDK.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"},{"id":"CWE-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not expire sessions by default, so repeated initialize requests retain unbounded ServerSession objects and can exhaust process memory. This issue is fixed in version 0.23.0.","ecosystems":["RubyGems"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood","id":"CVE-2026-67430","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"RubyGems","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":2,"n_references":3,"next":{"headline":"MCP Ruby SDK: Ruby SSE Session Poisoning","id":"CVE-2026-67431"},"packages":[{"ecosystem":"RubyGems","fixed":["0.23.0"],"introduced":["0"],"last_affected":[],"package":"mcp","purl":null,"source":"GHSA-52jp-gj8w-j6xh"},{"ecosystem":"RubyGems","fixed":["0.23.0"],"introduced":["0"],"last_affected":[],"package":"mcp","purl":"pkg:gem/mcp","source":"GHSA-52jp-gj8w-j6xh"}],"prev":{"headline":"Flyto2 Core: Arbitrary file write via image.download (and other file-writing modules)","id":"CVE-2026-67429"},"products":["ruby-sdk"],"published":"2026-07-29","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-30","vendors":["modelcontextprotocol"]},"summary":"Attackers can exhaust server memory by flooding initialize requests due to unbounded session retention in the MCP Ruby SDK.","url":"https://insights.sbomify.com/CVE-2026-67430/"}