{"id":"CVE-2023-35926","aliases":["EUVD-2023-1899","GHSA-wg6p-jmpc-xjmr"],"status":"published","title":"Insecure sandbox in Backstage Scaffolder plugin","description":"Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01888,"percentile":0.79707,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-94"],"published":"2023-06-21T22:00:30Z","modified":"2026-10-28T02:30:31Z","fixes":[{"ecosystem":"npm","package":"@backstage/plugin-scaffolder-backend","fixed_in":["1.15.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@backstage/plugin-scaffolder-backend","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.15.0"}]}]},{"source":"osv","ecosystem":"npm","package":"@backstage/plugin-scaffolder-backend","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.15.0"}]}]}],"products":[{"vendor":"backstage","product":"backstage"},{"vendor":"linuxfoundation","product":"backstage"}],"references":[{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-wg6p-jmpc-xjmr","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory","web"]},{"url":"https://github.com/backstage/backstage/commit/fb7375507d56faedcb7bb3665480070593c8949a","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.15.0","tags":["x_refsource_MISC","x_transferred","Release Notes","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-35926","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wg6p-jmpc-xjmr"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/35xxx/CVE-2023-35926.json","tags":["advisory"]},{"url":"https://github.com/backstage/backstage","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-35926","title":"Insecure sandbox in Backstage Scaffolder plugin","description":"Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.","status":"published","published":"2023-06-22T13:29:03.361Z","modified":"2024-12-05T17:48:07.987Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T14:35:33.794347Z"}],"euvd":[{"id":"EUVD-2023-1899","description":"Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.","status":"published","published":"2023-06-22T13:29:03Z","modified":"2024-12-05T17:48:07Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T00:04:39.661841Z"}],"ghsa":[{"id":"GHSA-wg6p-jmpc-xjmr","title":"Backstage Scaffolder plugin has insecure sandbox","description":"The Backstage scaffolder-backend plugin uses a templating library that requires a sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library.\n\n### Impact\n\nA malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data.\n\n### Patches\n\nThis is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.\n\n### Workarounds\n\nNote that the [Backstage Threat Model](https://backstage.io/docs/overview/threat-model) states that scaffolder templates are considered to be a sensitive area that with the recommendation that you control access and perform manual reviews of changes to the scaffolder templates. The exploit is of a nature where it is easily discoverable in manual review.","status":"published","published":"2023-06-21T22:00:30Z","modified":"2023-11-11T05:05:26Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T14:37:20.311836Z"}],"nvd":[{"id":"CVE-2023-35926","description":"Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.","status":"published","published":"2023-06-22T14:15:09.607Z","modified":"2026-06-17T06:05:28.84Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":9.9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T14:08:12.414559Z"}],"osv":[{"id":"CVE-2023-35926","title":"Insecure sandbox in Backstage Scaffolder plugin","description":"Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.","status":"published","published":"2023-06-22T13:29:03.361Z","modified":"2026-10-28T02:30:31.986545031Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T15:44:32.510144Z"},{"id":"GHSA-wg6p-jmpc-xjmr","title":"Backstage Scaffolder plugin has insecure sandbox","description":"The Backstage scaffolder-backend plugin uses a templating library that requires a sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities  that may not have a fix, the plugin has switched to using a different sandbox library.\n\n### Impact\n\nA malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data.\n\n### Patches\n\nThis is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.\n\n### Workarounds\n\nNote that the [Backstage Threat Model](https://backstage.io/docs/overview/threat-model) states that scaffolder templates are considered to be a sensitive area that with the recommendation that you control access and perform manual reviews of changes to the scaffolder templates. The exploit is of a nature where it is easily discoverable in manual review.","status":"published","published":"2023-06-21T22:00:30Z","modified":"2026-09-10T03:50:02.364560847Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T15:46:58.767335Z"}]}}