{"id":"CVE-2026-106457","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-106457","generatedAt":"2026-10-28T01:11:55.087Z","title":"Backstage is an open framework for building developer portals.","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.","published":"2026-10-06T21:17:16.000Z","lastModified":"2026-10-27T20:48:51.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-287"],"affected":["linuxfoundation/backstage\\/plugin-auth-backend-module-cloudflare-access-provider","linuxfoundation/backstage"],"epss":{"score":0.00278,"percentile":0.20032,"date":"2026-10-26","history":[{"date":"2026-10-07","score":0.00277,"percentile":0.18491}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-27T23:00:05.000Z","detail":{"from":"6.8","score":"8.1","severity":"HIGH","fromSeverity":"MEDIUM"},"summary":"Now scored CVSS 8.1 HIGH (was 6.8)."},{"kind":"new","label":"New CVE","at":"2026-10-06T21:17:16.000Z","detail":{"score":"6.8","severity":"MEDIUM","publishedAt":"2026-10-06T21:17:16.083Z"},"summary":"New CVE, high severity (CVSS 8.1)."}],"references":[{"url":"https://github.com/backstage/backstage/commit/ed9034cacd9def3b3674f0a764fe992f751e204d","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/releases/tag/v1.55.0","tags":["Patch","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-q333-f498-w2x7","tags":["Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-106457","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}