Skip to content
Heist/ feed
Back to feed
Medium

Sandbox escape for instances that have enabled transformation functions in matrix-hookshot

Type: advisorySources: OSV

matrix-hookshot is a Matrix bot for connecting to external services like GitHub, GitLab, JIRA, and more. Instances that have enabled transformation functions (those that have `generic.allowJsTransformationFunctions` in their config), may be vulnerable to an attack where it is possible to break out of the `vm2` sandbox and as a result Hookshot will be vulnerable to this. This problem is only likely to affect users who have allowed untrusted users to apply their own transformation functions. If you have only enabled a limited set of trusted users, this threat is reduced (though not eliminated). Version 4.5.0 and above of hookshot include a new sandbox library which should better protect users. Users are advised to upgrade. Users unable to upgrade should disable `generic.allowJsTransformationFunctions` in the config.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2023-43656
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 19:11 UTC · Revision 1

Source evidence

Sandbox escape for instances that have enabled transformation functions in matrix-hookshot

core-osv · Original source

Published 27 Sept 2023, 20:38 UTC

matrix-hookshot is a Matrix bot for connecting to external services like GitHub, GitLab, JIRA, and more. Instances that have enabled transformation functions (those that have `generic.allowJsTransformationFunctions` in their config), may be vulnerable to an attack where it is possible to break out of the `vm2` sandbox and as a result Hookshot will be vulnerable to this. This problem is only likely to affect users who have allowed untrusted users to apply their own transformation functions. If you have only enabled a limited set of trusted users, this threat is reduced (though not eliminated). Version 4.5.0 and above of hookshot include a new sandbox library which should better protect users. Users are advised to upgrade. Users unable to upgrade should disable `generic.allowJsTransformationFunctions` in the config.

osv:CVE-2023-43656
Complete source record
{
  "id": "d232bc110ff6a6f60ae15ae9cbe29138499aabb068476171dd5b071328c4760c",
  "url": "https://osv.dev/vulnerability/CVE-2023-43656",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Sandbox escape for instances that have enabled transformation functions in matrix-hookshot",
    "summary": "matrix-hookshot is a Matrix bot for connecting to external services like GitHub, GitLab, JIRA, and more. Instances that have enabled transformation functions (those that have `generic.allowJsTransformationFunctions` in their config), may be vulnerable to an attack where it is possible to break out of the `vm2` sandbox and as a result Hookshot will be vulnerable to this. This problem is only likely to affect users who have allowed untrusted users to apply their own transformation functions. If you have only enabled a limited set of trusted users, this threat is reduced (though not eliminated). Version 4.5.0 and above of hookshot include a new sandbox library which should better protect users. Users are advised to upgrade. Users unable to upgrade should disable `generic.allowJsTransformationFunctions` in the config.",
    "evidence": "osv:CVE-2023-43656",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2023-43656",
      "aliases": [
        "CVE-2023-43656",
        "GHSA-fr97-pv6w-4cj6"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/matrix-org/matrix-hookshot",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "257c93e0e0a5d1285c70841411e6c5f6f42faadd"
                },
                {
                  "fixed": "dc126afa6af86d66aefcd23a825326f405bcc894"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:matrix:hookshot:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.5.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "dc126afa6af86d66aefcd23a825326f405bcc894"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.4.1",
            "4.3.0",
            "helm-hookshot-0.1.13",
            "4.2.0",
            "4.1.0",
            "4.0.0",
            "3.2.0",
            "3.1.1",
            "3.1.0",
            "3.0.1",
            "3.0.0",
            "2.7.0",
            "2.6.1",
            "2.5.0",
            "2.4.0",
            "2.3.0",
            "2.2.0",
            "2.1.2",
            "2.1.1",
            "2.1.0",
            "2.0.1",
            "2.0.0",
            "1.8.1",
            "1.8.0",
            "1.7.3",
            "1.7.2",
            "1.7.1",
            "1.7.0",
            "1.6.0",
            "1.5.0",
            "1.4.0",
            "1.3.0",
            "1.2.0",
            "1.1.0",
            "1.0.0",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-43656.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.932305677Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43656.json",
        "https://github.com/matrix-org/matrix-hookshot/security/advisories/GHSA-fr97-pv6w-4cj6",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-43656",
        "https://github.com/matrix-org/matrix-hookshot/commit/dc126afa6af86d66aefcd23a825326f405bcc894"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-74"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43656.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-43656",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489002,
  "published_at": "2023-09-27T20:38:57.46+00:00"
}