{"id":"CVE-2026-106503","title":"Backstage is an open framework for building developer portals","summary":"Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by scaffolder action input authorization bypass. An authenticated user wi…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-178","CWE-284","CWE-807"],"vendor":"linuxfoundation","product":"backstage/plugin-scaffolder-backend","affected":["backstage/plugin-scaffolder-backend < 3.3.1","backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1","backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3","backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0","backstage < 1.49.6","backstage >= 1.50.0, < 1.50.5","backstage >= 1.51.0, < 1.54.6"],"patched":["backstage/plugin-scaffolder-backend 4.1.0","backstage 1.54.6"],"published":"2026-10-06","updated":"2026-10-13","sourceUpdated":"2026-10-13T14:37:56.910","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-106503","references":[{"url":"https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bf","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/releases/tag/v1.49.6","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/releases/tag/v1.50.5","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/releases/tag/v1.54.6","label":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cv","label":"security-advisories@github.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-106503"},{"url":"https://github.com/advisories/GHSA-hmp2-4m7g-22cv"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-106503.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-106503"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2547234"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-106503"},{"url":"https://access.redhat.com/errata/RHSA-2026:86675"}],"tags":["nvd","cve.org","ghsa","npm","csaf","vex","red-hat"],"epss":0.00391,"epssPercentile":0.33017,"aliases":["GHSA-hmp2-4m7g-22cv"],"ecosystem":"npm","ingestedAt":"2026-10-06T22:23:15.967Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-09T01:55:45.447568Z"},"slug":"CVE-2026-106503","body":"## Overview\n\nBackstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by scaffolder action input authorization bypass. An authenticated user with access to affected Scaffolder templates could bypass configured action restrictions. Depending on integration credentials, this could grant unauthorized access to repositories and related source-control resources. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.\n\n## Affected\n\n- `backstage/plugin-scaffolder-backend < 3.3.1`\n- `backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1`\n- `backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3`\n- `backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0`\n- `backstage < 1.49.6`\n- `backstage >= 1.50.0, < 1.50.5`\n- `backstage >= 1.51.0, < 1.54.6`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `backstage/plugin-scaffolder-backend 4.1.0`\n- `backstage 1.54.6`\n\n## Package advisory (CVE-2026-106503)\n\nAffected packages:\n\n- `@backstage/plugin-scaffolder-backend < 3.3.1`\n- `@backstage/plugin-scaffolder-backend >= 3.4.0, < 3.4.1`\n- `@backstage/plugin-scaffolder-backend >= 4.0.0, < 4.0.3`\n- `@backstage/plugin-scaffolder-backend >= 4.0.4, < 4.1.0`\n\nPatched in:\n\n- `@backstage/plugin-scaffolder-backend 3.3.1`\n- `@backstage/plugin-scaffolder-backend 3.4.1`\n- `@backstage/plugin-scaffolder-backend 4.0.3`\n- `@backstage/plugin-scaffolder-backend 4.1.0`\n\nSource: https://github.com/advisories/GHSA-hmp2-4m7g-22cv\n\n## Vendor advisories\n\n- **RHSA-2026:86675** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.2 · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:86675)\n- **Red Hat VEX** · Important · affected: Red Hat Developer Hub, Self-service automation portal 2 · no fix planned: Red Hat Developer Hub, Self-service automation portal 2 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-106503.json)","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}