{"id":"CVE-2026-32235","state":"PUBLISHED","title":"@backstage/plugin-auth-backend: OAuth redirect URI allowlist bypass","description":"Backstage is an open framework for building developer portals. Prior to 0.27.1, the experimental OIDC provider in @backstage/plugin-auth-backend is vulnerable to a redirect URI allowlist bypass. Instances that have enabled experimental Dynamic Client Registration or Client ID Metadata Documents and configured allowedRedirectUriPatterns are affected. A specially crafted redirect URI can pass the allowlist validation while resolving to an attacker-controlled host. If a victim approves the resulting OAuth consent request, their authorization code is sent to the attacker, who can exchange it for a valid access token. This requires victim interaction and that one of the experimental features is explicitly enabled, which is not the default. This vulnerability is fixed in 0.27.1.","publishedAt":"2026-03-12T18:35:06.325Z","updatedAt":"2026-03-12T20:46:46.618Z","severity":{"score":5.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["@backstage plugin-auth-backend"],"affected":[{"vendor":"@backstage","product":"plugin-auth-backend","versions":[{"version":"< 0.27.1","status":"affected"}]}],"references":["https://github.com/backstage/backstage/security/advisories/GHSA-wqvh-63mv-9w92"],"weaknesses":["CWE-601"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/32xxx/CVE-2026-32235.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-32235","state":"PUBLISHED","datePublished":"2026-03-12T18:35:06.325Z","dateUpdated":"2026-03-12T20:46:46.618Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-11T14:47:05.683Z"},"containers":{"cna":{"title":"@backstage/plugin-auth-backend: OAuth redirect URI allowlist bypass","descriptions":[{"lang":"en","value":"Backstage is an open framework for building developer portals. Prior to 0.27.1, the experimental OIDC provider in @backstage/plugin-auth-backend is vulnerable to a redirect URI allowlist bypass. Instances that have enabled experimental Dynamic Client Registration or Client ID Metadata Documents and configured allowedRedirectUriPatterns are affected. A specially crafted redirect URI can pass the allowlist validation while resolving to an attacker-controlled host. If a victim approves the resulting OAuth consent request, their authorization code is sent to the attacker, who can exchange it for a valid access token. This requires victim interaction and that one of the experimental features is explicitly enabled, which is not the default. This vulnerability is fixed in 0.27.1."}],"affected":[{"vendor":"@backstage","product":"plugin-auth-backend","versions":[{"version":"< 0.27.1","status":"affected"}]}],"references":[{"url":"https://github.com/backstage/backstage/security/advisories/GHSA-wqvh-63mv-9w92","name":"https://github.com/backstage/backstage/security/advisories/GHSA-wqvh-63mv-9w92","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-601","lang":"en","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-12T18:35:06.325Z"},"source":{"advisory":"GHSA-wqvh-63mv-9w92","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-12T20:38:14.280151Z","id":"CVE-2026-32235","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-12T20:46:46.618Z"}}]}}}