{"cve":"CVE-2026-106509","nvd":{"published":"2026-10-06T22:17:06.463","modified":"2026-10-09T17:34:17.120","status":"Analyzed","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When 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. This issue is fixed in versions 1.14.6 and 1.15.4.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-94","CWE-1336"],"references":["https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb","https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d","https://github.com/backstage/backstage/releases/tag/v1.50.5","https://github.com/backstage/backstage/releases/tag/v1.54.6","https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c"],"products":["linuxfoundation:backstage","linuxfoundation:backstage_plugin-techdocs-node"],"source":"nvd","synced_at":"2026-10-19T22:58:01.639778232+00:00"},"epss":{"cve":"CVE-2026-106509","score":0.00516,"percentile":0.43681,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-8w7q-29mw-gf5c","url":"https://osv.dev/vulnerability/GHSA-8w7q-29mw-gf5c","summary":"Backstage: Improper validation of MkDocs theme configuration in TechDocs","modified":"2026-10-07T16:30:04.718106469Z","packages":[{"ecosystem":"npm","name":"@backstage/plugin-techdocs-node","purl":"pkg:npm/%40backstage/plugin-techdocs-node","ranges":["<1.15.4"],"fixed":["1.15.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}