{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0"
                  },
                  {
                    "fixed": "0.0.75"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "22b8ee60eb92128cf4ff04a9b6c0e1b62bf25a01"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "range": [
                  {
                    "fixed": "6c6213f88dfa8b2a70d23a9a271171241e910904"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v0.0.75",
                "range": [
                  {
                    "fixed": "6c6213f88dfa8b2a70d23a9a271171241e910904"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6c6213f88dfa8b2a70d23a9a271171241e910904"
            },
            {
              "fixed": "22b8ee60eb92128cf4ff04a9b6c0e1b62bf25a01"
            }
          ],
          "repo": "https://github.com/heymrun/heym",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-378x-q589-34mv"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67546.json"
  },
  "details": "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.",
  "id": "CVE-2026-67546",
  "modified": "2026-11-12T10:31:00.927416849Z",
  "published": "2026-11-11T21:41:03.020Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67546.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/heymrun/heym/commit/22b8ee60eb92128cf4ff04a9b6c0e1b62bf25a01"
    },
    {
      "type": "FIX",
      "url": "https://github.com/heymrun/heym/commit/6c6213f88dfa8b2a70d23a9a271171241e910904"
    },
    {
      "type": "WEB",
      "url": "https://github.com/heymrun/heym/releases/tag/v0.0.75"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/heymrun/heym/security/advisories/GHSA-378x-q589-34mv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-67546"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Heym: Command execution via POST /api/mcp/fetch-tools stdio transport: supplied command is spawned before MCP validation"
}