{"id":"CVE-2026-106557","aliases":["EUVD-2026-94482","GHSA-f7v3-xhm6-w245"],"status":"published","title":"Backstage: Improper input validation in TechDocs Markdown extension configuration","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.","severity":{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00375,"percentile":0.31902,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22","CWE-918"],"published":"2026-10-07T16:22:53Z","modified":"2026-10-28T02:30:50Z","fixes":[{"ecosystem":"npm","package":"@backstage/plugin-techdocs-node","fixed_in":["1.15.4"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@backstage/plugin-techdocs-node","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.15.4"}]}]},{"source":"osv","ecosystem":"npm","package":"@backstage/plugin-techdocs-node","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.15.4"}]}]}],"products":[{"vendor":"@backstage","product":"plugin-techdocs-node"},{"vendor":"backstage","product":"backstage"}],"references":[{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.50.5","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.54.6","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/advisories/GHSA-f7v3-xhm6-w245"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106557.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-106557","tags":["advisory"]},{"url":"https://github.com/backstage/backstage","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-106557","title":"Backstage: Improper input validation in TechDocs Markdown extension configuration","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.","status":"published","published":"2026-10-07T16:22:53.32Z","modified":"2026-10-07T17:47:16.631Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-22","CWE-918"],"updated_at":"2026-11-02T14:20:04.156238Z"}],"euvd":[{"id":"EUVD-2026-94482","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.","status":"published","published":"2026-10-07T16:22:53Z","modified":"2026-10-07T17:47:16Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T17:27:34.815018Z"}],"ghsa":[{"id":"GHSA-f7v3-xhm6-w245","title":"Backstage has improper input validation in TechDocs Markdown extension configuration","description":"### Impact\n\nAn authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary. Depending on deployment configuration, this may expose sensitive backend-host data or internal network resources.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version `1.15.4`.\n\nAdopters must also use `pymdown-extensions` version `10.21.3` or newer, normally through `mkdocs-techdocs-core` version `1.7.0` or newer. `@backstage/plugin-techdocs-node` does not control the Python dependencies used by the generator; with an older PyMdown release, snippets may remain vulnerable to file inclusion even after their configuration is sanitized.\n\n### Workarounds\n\n- Generate TechDocs only from trusted repositories with reviewed MkDocs configuration.\n- Use isolated build environments with restricted filesystem access and network egress.\n- Prefer externally generated TechDocs with appropriately sandboxed CI.","status":"published","published":"2026-10-07T16:22:58Z","modified":"2026-10-07T16:22:59Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-22","CWE-918"],"updated_at":"2026-11-02T14:41:28.013673Z"}],"nvd":[{"id":"CVE-2026-106557","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.","status":"published","published":"2026-10-07T17:16:50.9Z","modified":"2026-10-08T21:33:42.423Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-22","CWE-918"],"updated_at":"2026-11-02T14:12:54.809359Z"}],"osv":[{"id":"CVE-2026-106557","title":"Backstage: Improper input validation in TechDocs Markdown extension configuration","description":"Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.","status":"published","published":"2026-10-07T16:22:53.32Z","modified":"2026-10-28T02:30:50.208219907Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-22","CWE-918"],"updated_at":"2026-11-02T15:44:54.583213Z"},{"id":"GHSA-f7v3-xhm6-w245","title":"Backstage has improper input validation in TechDocs Markdown extension configuration","description":"### Impact\n\nAn authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary. Depending on deployment configuration, this may expose sensitive backend-host data or internal network resources.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version `1.15.4`.\n\nAdopters must also use `pymdown-extensions` version `10.21.3` or newer, normally through `mkdocs-techdocs-core` version `1.7.0` or newer. `@backstage/plugin-techdocs-node` does not control the Python dependencies used by the generator; with an older PyMdown release, snippets may remain vulnerable to file inclusion even after their configuration is sanitized.\n\n### Workarounds\n\n- Generate TechDocs only from trusted repositories with reviewed MkDocs configuration.\n- Use isolated build environments with restricted filesystem access and network egress.\n- Prefer externally generated TechDocs with appropriately sandboxed CI.","status":"published","published":"2026-10-07T16:22:58Z","modified":"2026-10-07T16:30:06.348764958Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-22","CWE-918"],"updated_at":"2026-11-02T15:46:46.006631Z"}]}}