{"id":"CVE-2026-106456","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-106456","generatedAt":"2026-10-28T01:11:58.090Z","title":"Backstage is an open framework for building developer portals.","description":"Backstage is an open framework for building developer portals. From 0.5.0 until 0.6.18, the @backstage/plugin-proxy-backend package is affected by inconsistent credential enforcement for overlapping proxy routes. An operator can configure overlapping proxy paths with different credential requirements. When a parent path permits unauthenticated access and a nested path requires credentials, the parent exemption can also cover requests handled by the nested proxy. An unauthenticated caller may therefore reach the nested upstream through Backstage, including with static upstream credentials configured for that proxy. This issue is fixed in version 0.6.18.","published":"2026-10-06T21:17:16.000Z","lastModified":"2026-10-27T20:51:43.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},"cwe":["CWE-863"],"affected":["linuxfoundation/backstage\\/plugin-proxy-backend","linuxfoundation/backstage"],"epss":{"score":0.00236,"percentile":0.14483,"date":"2026-10-26","history":[{"date":"2026-10-07","score":0.00236,"percentile":0.13373}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-27T23:00:05.000Z","detail":{"from":"4.8","score":"6.5","severity":"MEDIUM","fromSeverity":"MEDIUM"},"summary":"Now scored CVSS 6.5 MEDIUM (was 4.8)."},{"kind":"new","label":"New CVE","at":"2026-10-06T21:17:16.000Z","detail":{"score":"4.8","severity":"MEDIUM","publishedAt":"2026-10-06T21:17:15.903Z"},"summary":"New CVE, medium severity (CVSS 6.5)."}],"references":[{"url":"https://github.com/backstage/backstage/commit/9df92923ac32558bb80edeceafd8de780c44e218","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-472h-9c5j-prrr","tags":["Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-106456","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."}