{"id":"CVE-2026-106509","state":"PUBLISHED","title":"Backstage: Improper validation of MkDocs theme configuration in TechDocs","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.","publishedAt":"2026-10-06T21:50:07.721Z","updatedAt":"2026-10-07T18:01:48.511Z","severity":{"score":7.7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["backstage backstage","@backstage plugin-techdocs-node"],"affected":[{"vendor":"backstage","product":"backstage","versions":[{"version":"< 1.50.5","status":"affected"},{"version":">= 1.51.0-next.0, < 1.54.6","status":"affected"}]},{"vendor":"@backstage","product":"plugin-techdocs-node","versions":[{"version":"< 1.14.6","status":"affected"},{"version":">= 1.15.0, < 1.15.4","status":"affected"}]}],"references":["https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c","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"],"weaknesses":["CWE-94","CWE-1336"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/106xxx/CVE-2026-106509.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-106509","state":"PUBLISHED","datePublished":"2026-10-06T21:50:07.721Z","dateUpdated":"2026-10-07T18:01:48.511Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-06T18:46:47.767Z"},"containers":{"cna":{"title":"Backstage: Improper validation of MkDocs theme configuration in TechDocs","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"backstage","product":"backstage","versions":[{"version":"< 1.50.5","status":"affected"},{"version":">= 1.51.0-next.0, < 1.54.6","status":"affected"}]},{"vendor":"@backstage","product":"plugin-techdocs-node","versions":[{"version":"< 1.14.6","status":"affected"},{"version":">= 1.15.0, < 1.15.4","status":"affected"}]}],"references":[{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c","name":"https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb","name":"https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb","tags":["x_refsource_MISC"]},{"url":"https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d","name":"https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d","tags":["x_refsource_MISC"]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.50.5","name":"https://github.com/backstage/backstage/releases/tag/v1.50.5","tags":["x_refsource_MISC"]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.54.6","name":"https://github.com/backstage/backstage/releases/tag/v1.54.6","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":7.7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code ('Code Injection')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-1336","lang":"en","description":"CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-06T21:50:07.721Z"},"source":{"advisory":"GHSA-8w7q-29mw-gf5c","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-07T18:01:39.138438Z","id":"CVE-2026-106509","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-07T18:01:48.511Z"}}]}}}