heym before 0.0.91 Remote Code Execution via Expression Engine

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-100864",
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "dateUpdated": "2026-09-27T01:28:53.237Z",
    "dateReserved": "2026-09-27T00:20:54.407Z",
    "datePublished": "2026-09-27T01:28:53.237Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck",
        "dateUpdated": "2026-09-27T01:28:53.237Z"
      },
      "datePublic": "2026-08-15T00:00:00.000Z",
      "title": "heym before 0.0.91 Remote Code Execution via Expression Engine",
      "descriptions": [
        {
          "lang": "en",
          "value": "heym before 0.0.91 contains a sandbox escape vulnerability in the expression engine's DotList map/filter and fallback resolver that allows authenticated users to execute arbitrary Python code. Attackers can craft workflow expressions using dunder attribute access through item expressions or the fallback resolver to access os.system and execute commands as the backend process."
        }
      ],
      "affected": [
        {
          "vendor": "heymrun",
          "product": "heym",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "0.0.91"
            },
            {
              "version": "0.0.91",
              "status": "unaffected",
              "versionType": "semver"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "Improper Control of Generation of Code ('Code Injection')",
              "cweId": "CWE-94",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/heymrun/heym/security/advisories/GHSA-87x2-9jwx-7gh4",
          "name": "GitHub Security Advisory (GHSA-87x2-9jwx-7gh4)",
          "tags": [
            "vendor-advisory"
          ]
        },
        {
          "url": "https://www.vulncheck.com/advisories/heym-before-0.0.91-remote-code-execution-via-expression-engine",
          "name": "VulnCheck Advisory: heym before 0.0.91 Remote Code Execution via Expression Engine",
          "tags": [
            "third-party-advisory"
          ]
        }
      ],
      "metrics": [
        {
          "format": "CVSS"
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "attackVector": "NETWORK",
            "attackComplexity": "LOW",
            "privilegesRequired": "LOW",
            "userInteraction": "NONE",
            "scope": "UNCHANGED",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH"
          }
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "mbakgun",
          "type": "finder"
        }
      ]
    }
  }
}