{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-67546","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-07-29T18:47:17.074Z","datePublished":"2026-11-11T21:41:03.020Z","dateUpdated":"2026-11-11T21:41:03.020Z"},"containers":{"cna":{"title":"Heym: Command execution via POST /api/mcp/fetch-tools stdio transport: supplied command is spawned before MCP validation","problemTypes":[{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"name":"https://github.com/heymrun/heym/security/advisories/GHSA-378x-q589-34mv","tags":["x_refsource_CONFIRM"],"url":"https://github.com/heymrun/heym/security/advisories/GHSA-378x-q589-34mv"},{"name":"https://github.com/heymrun/heym/commit/22b8ee60eb92128cf4ff04a9b6c0e1b62bf25a01","tags":["x_refsource_MISC"],"url":"https://github.com/heymrun/heym/commit/22b8ee60eb92128cf4ff04a9b6c0e1b62bf25a01"},{"name":"https://github.com/heymrun/heym/commit/6c6213f88dfa8b2a70d23a9a271171241e910904","tags":["x_refsource_MISC"],"url":"https://github.com/heymrun/heym/commit/6c6213f88dfa8b2a70d23a9a271171241e910904"},{"name":"https://github.com/heymrun/heym/releases/tag/v0.0.75","tags":["x_refsource_MISC"],"url":"https://github.com/heymrun/heym/releases/tag/v0.0.75"}],"affected":[{"vendor":"heymrun","product":"heym","versions":[{"version":"< 0.0.75","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-11-11T21:41:03.020Z"},"descriptions":[{"lang":"en","value":"Heym builds and runs agentic systems and business-process automations on self-hosted infrastructure. Prior to version 0.0.75, the same POST /api/mcp/fetch-tools endpoint (any authenticated user, lowest role) also accepts the stdio transport, which spawns the attacker-supplied command with attacker-supplied args and an environment merged over os.environ. The process executes on the shared backend host before MCP protocol validation fails — so side effects fire regardless of whether the command speaks MCP. This is a distinct weakness class and exploit primitive from the SSRF (Advisory 2) on the same endpoint, and needs a different fix (role gating / opt-in trust boundary rather than egress controls). This issue has been patched in version 0.0.75."}],"source":{"advisory":"GHSA-378x-q589-34mv","discovery":"UNKNOWN"}}}}