{"id":"GHSA-8w7q-29mw-gf5c","summary":"Backstage: Improper validation of MkDocs theme configuration in TechDocs","details":"### Impact\n\nWhen TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in `mkdocs.yml` that cause arbitrary code execution during the documentation build process.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version `1.15.4`\n\n### Workarounds\n\n- Configure TechDocs with `techdocs.generator.runIn: 'docker'` instead of `'local'` to provide container isolation, though this does not fully mitigate the risk.\n- Restrict write access to repositories registered in the Backstage catalog to trusted users.","aliases":["CVE-2026-106509"],"modified":"2026-10-07T16:30:04.718106469Z","published":"2026-10-07T16:23:30Z","database_specific":{"cwe_ids":["CWE-1336","CWE-94"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-10-07T16:23:30Z","nvd_published_at":"2026-10-06T22:17:06Z"},"references":[{"type":"WEB","url":"https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-106509"},{"type":"WEB","url":"https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb"},{"type":"WEB","url":"https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d"},{"type":"PACKAGE","url":"https://github.com/backstage/backstage"},{"type":"WEB","url":"https://github.com/backstage/backstage/releases/tag/v1.50.5"},{"type":"WEB","url":"https://github.com/backstage/backstage/releases/tag/v1.54.6"}],"affected":[{"package":{"name":"@backstage/plugin-techdocs-node","ecosystem":"npm","purl":"pkg:npm/%40backstage/plugin-techdocs-node"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.15.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-8w7q-29mw-gf5c/GHSA-8w7q-29mw-gf5c.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L"}]}