{"id":"CVE-2026-106492","published":"2026-10-06T21:17:18.220","lastModified":"2026-10-09T02:17:00.467","description":"Backstage is an open framework for building developer portals. Prior to 0.16.1 and 0.17.8, the @backstage/backend-defaults package is affected by improper preservation of access restrictions during service credential delegation. An external service credential configured with access restrictions (e.g., read-only) could bypass those restrictions by routing requests through plugin delegation paths. This could allow a restricted service to perform operations beyond its intended scope, including write operations on plugins it was restricted to read-only access for. This issue is fixed in versions 0.16.1 and 0.17.8.","cvssScore":7.6,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L","cwes":["CWE-269","CWE-863"],"vendors":[],"products":[],"references":[{"url":"https://github.com/backstage/backstage/commit/40346245c53e1bf26dee56601e95c5c4ab9cc124","tags":[]},{"url":"https://github.com/backstage/backstage/commit/bc80ffdafbc92ff7b8c72347eace13cb8688fd33","tags":[]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.49.6","tags":[]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.54.6","tags":[]},{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-cq7v-rfgc-5c7v","tags":[]}],"exploitRefs":[{"url":"https://github.com/backstage/backstage/commit/40346245c53e1bf26dee56601e95c5c4ab9cc124","tags":[]},{"url":"https://github.com/backstage/backstage/commit/bc80ffdafbc92ff7b8c72347eace13cb8688fd33","tags":[]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.49.6","tags":[]},{"url":"https://github.com/backstage/backstage/releases/tag/v1.54.6","tags":[]},{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-cq7v-rfgc-5c7v","tags":[]}],"hasPoc":true,"ai":{"summary":"A vulnerability in Backstage's @backstage/backend-defaults package allows restricted service credentials to bypass access restrictions during plugin delegation, potentially enabling unauthorized write operations beyond their intended read-only scope.","exploitability":"Exploitation requires an attacker to have access to a service credential with restricted permissions and to be able to route requests through plugin delegation paths, making it moderately difficult to exploit without prior access.","blast_radius":"If exploited, this vulnerability could allow attackers to perform unauthorized write operations on plugins they were originally restricted from modifying, potentially leading to data corruption or privilege escalation within the developer portal.","remediation":"Upgrade to version 0.16.1 or 0.17.8 to fix the access restriction bypass issue in @backstage/backend-defaults package.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","access-control","developer-portal"],"model":"garnet-coder","analyzedAt":"2026-10-15T09:01:45.133Z"}}