{"cve":"CVE-2026-106457","nvd":{"published":"2026-10-06T21:17:16.083","modified":"2026-10-07T16:17:38.710","status":"Undergoing Analysis","description":"Backstage is an open framework for building developer portals. From 0.1.0 until 0.5.0, the @backstage/plugin-auth-backend-module-cloudflare-access-provider package is affected by insufficient audience validation in the cloudflare access auth provider. The Cloudflare Access auth provider verifies a token's signature and team issuer, but affected versions do not verify that the token was issued for the Backstage application. A user holding a valid token for another Access application in the same Cloudflare Zero Trust team may therefore be able to authenticate to Backstage if that token reaches the auth endpoint without the Backstage application's audience already being enforced upstream. Cloudflare Access normally evaluates the protected application before forwarding requests. This issue is fixed in version 0.5.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","score":6.8},"cwes":["CWE-287"],"references":["https://github.com/backstage/backstage/commit/ed9034cacd9def3b3674f0a764fe992f751e204d","https://github.com/backstage/backstage/releases/tag/v1.55.0","https://github.com/backstage/backstage/security/advisories/GHSA-q333-f498-w2x7"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:58:01.639778232+00:00"},"epss":{"cve":"CVE-2026-106457","score":0.00278,"percentile":0.20015,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-q333-f498-w2x7","url":"https://osv.dev/vulnerability/GHSA-q333-f498-w2x7","summary":"Backstage: Insufficient audience validation in the Cloudflare Access auth provider","modified":"2026-10-07T20:30:04.832917243Z","packages":[{"ecosystem":"npm","name":"@backstage/plugin-auth-backend-module-cloudflare-access-provider","purl":"pkg:npm/%40backstage/plugin-auth-backend-module-cloudflare-access-provider","ranges":[">=0.1.0 <0.5.0"],"fixed":["0.5.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}