{"id":"GHSA-9ghw-48h5-v2w5","revision":"a392b33a69a74be287b2b114b0dacecf","records":[{"revision":"a392b33a69a74be287b2b114b0dacecf","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-9ghw-48h5-v2w5","aliases":["CVE-2026-106491"],"title":"Backstage: Improper input validation in proxy-backend","description":"### Impact\n\nAn authenticated Backstage user could craft a request URL that causes the proxy-backend to forward the request to a path outside the configured base path on the target server. This is limited to target servers already configured as proxy endpoints and requires Backstage authentication by default.\n\n### Patches\n\nPatched in `@backstage/plugin-proxy-backend` version `0.6.17`\n\n### Workarounds\n\n- Deploy a reverse proxy or WAF in front of Backstage that normalizes request paths before they reach the backend.","state":0,"publishedAt":"2026-10-07T17:59:49+00:00","modifiedAt":"2026-10-07T18:15:11.7665014+00:00","affected":[{"ecosystem":"npm","name":"@backstage/plugin-proxy-backend","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"0.6.17"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/backstage/backstage/security/advisories/GHSA-9ghw-48h5-v2w5","https://nvd.nist.gov/vuln/detail/CVE-2026-106491","https://github.com/backstage/backstage/commit/233287d0ce3133e41549bf92a7470c940a41753c","https://github.com/backstage/backstage","https://github.com/backstage/backstage/releases/tag/v1.54.6"],"sourceUrl":"https://github.com/advisories/GHSA-9ghw-48h5-v2w5","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-9ghw-48h5-v2w5","identifiers":["GHSA-9ghw-48h5-v2w5","CVE-2026-106491"]},"retained":false,"historicalAffected":[]}],"coverage":[]}