CVE-2026-73563

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-73563", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-12T20:53:46.380Z", "datePublished": "2026-08-13T17:32:39.535Z", "dateUpdated": "2026-08-13T18:07:45.624Z"}, "containers": {"cna": {"title": "Backstage: Unauthenticated OAuth account takeover via `redirect_uri` allowlist bypass in `@backstage/plugin-auth-backend`", "problemTypes": [{"descriptions": [{"cweId": "CWE-601", "lang": "en", "description": "CWE-601: URL Redirection to Untrusted Site ('Open Redirect')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4"}], "affected": [{"vendor": "backstage", "product": "backstage", "versions": [{"version": "< 0.29.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-13T17:32:39.535Z"}, "descriptions": [{"lang": "en", "value": "Backstage is an open framework for building developer portals. Prior to 0.29.2, the experimental dynamic client registration and client ID metadata document features in the @backstage/plugin-auth-backend use full-string matcher.isMatch glob matching for auth.experimentalDynamicClientRegistration.allowedRedirectUriPatterns and the auth.experimentalClientIdMetadataDocuments allowedClientIdPatterns and allowedRedirectUriPatterns options. A hostname wildcard can match across URL component boundaries, allowing an attacker-controlled redirect URI with a trusted hostname suffix in its path to pass the allowlist and receive an OAuth authorization code after a victim completes the flow. Patterns without an explicit protocol can match unintended protocols, and redirect URIs containing embedded credentials are accepted after user information is stripped for matching. The features are experimental and disabled by default; only deployments that enable them and configure custom wildcard-hostname or protocol-less patterns are affected. This issue is first fixed in prerelease version 0.29.2."}], "source": {"advisory": "GHSA-38hq-7x33-php4", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-13T18:07:39.895342Z", "id": "CVE-2026-73563", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-13T18:07:45.624Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-73563", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-13T18:07:39.895342Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-13T18:07:42.523Z"}}], "cna": {"title": "Backstage: Unauthenticated OAuth account takeover via `redirect_uri` allowlist bypass in `@backstage/plugin-auth-backend`", "source": {"advisory": "GHSA-38hq-7x33-php4", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "CHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}}], "affected": [{"vendor": "backstage", "product": "backstage", "versions": [{"status": "affected", "version": "< 0.29.2"}]}], "references": [{"url": "https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4", "name": "https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4", "tags": ["x_refsource_CONFIRM"]}], "descriptions": [{"lang": "en", "value": "Backstage is an open framework for building developer portals. Prior to 0.29.2, the experimental dynamic client registration and client ID metadata document features in the @backstage/plugin-auth-backend use full-string matcher.isMatch glob matching for auth.experimentalDynamicClientRegistration.allowedRedirectUriPatterns and the auth.experimentalClientIdMetadataDocuments allowedClientIdPatterns and allowedRedirectUriPatterns options. A hostname wildcard can match across URL component boundaries, allowing an attacker-controlled redirect URI with a trusted hostname suffix in its path to pass the allowlist and receive an OAuth authorization code after a victim completes the flow. Patterns without an explicit protocol can match unintended protocols, and redirect URIs containing embedded credentials are accepted after user information is stripped for matching. The features are experimental and disabled by default; only deployments that enable them and configure custom wildcard-hostname or protocol-less patterns are affected. This issue is first fixed in prerelease version 0.29.2."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-601", "description": "CWE-601: URL Redirection to Untrusted Site ('Open Redirect')"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-13T17:32:39.535Z"}}}, "cveMetadata": {"cveId": "CVE-2026-73563", "state": "PUBLISHED", "dateUpdated": "2026-08-13T18:07:45.624Z", "dateReserved": "2026-08-12T20:53:46.380Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-08-13T17:32:39.535Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "backstage", "vendor": "backstage", "versions": [{"status": "affected", "version": "< 0.29.2"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:linuxfoundation:backstage\\/plugin-auth-backend:*:*:*:*:*:node.js:*:*", "matchCriteriaId": "B087DDFF-EF94-42A0-A164-25CD7CDACBEE", "versionEndExcluding": "0.29.2", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Backstage is an open framework for building developer portals. Prior to 0.29.2, the experimental dynamic client registration and client ID metadata document features in the @backstage/plugin-auth-backend use full-string matcher.isMatch glob matching for auth.experimentalDynamicClientRegistration.allowedRedirectUriPatterns and the auth.experimentalClientIdMetadataDocuments allowedClientIdPatterns and allowedRedirectUriPatterns options. A hostname wildcard can match across URL component boundaries, allowing an attacker-controlled redirect URI with a trusted hostname suffix in its path to pass the allowlist and receive an OAuth authorization code after a victim completes the flow. Patterns without an explicit protocol can match unintended protocols, and redirect URIs containing embedded credentials are accepted after user information is stripped for matching. The features are experimental and disabled by default; only deployments that enable them and configure custom wildcard-hostname or protocol-less patterns are affected. This issue is first fixed in prerelease version 0.29.2."}], "id": "CVE-2026-73563", "lastModified": "2026-10-15T20:37:36.210", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73563", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-13T18:07:39.895342Z", "version": "2.0.3"}}]}, "published": "2026-08-13T18:18:18.803", "references": [{"source": "security-advisories@github.com", "tags": ["Mitigation", "Vendor Advisory"], "url": "https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-601"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "@backstage/plugin-auth-backend: Backstage: Unauthenticated OAuth account takeover via `redirect_uri` allowlist bypass", "id": "2515512", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2515512"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.0", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N", "status": "draft"}, "cwe": "CWE-1289", "details": ["A flaw was found in the `@backstage/plugin-auth-backend` component of Backstage. This vulnerability allows an unauthenticated remote attacker to bypass the `redirect_uri` allowlist in the experimental dynamic client registration feature. By crafting a malicious redirect Uniform Resource Identifier (URI) with a trusted hostname suffix, an attacker can receive an OAuth authorization code, potentially leading to an account takeover. This issue affects deployments that have enabled the experimental features and configured custom wildcard-hostname or protocol-less patterns."], "mitigation": {"lang": "en:us", "value": "Do not enable the experimental dynamic client registration or client ID metadata document features. If these features are currently enabled, review and restrict the allowedRedirectUriPatterns and allowedClientIdPatterns configurations to use fully qualified hostnames with explicit protocols rather than wildcard or protocol-less patterns."}, "name": "CVE-2026-73563", "package_state": [{"cpe": "cpe:/a:redhat:rhdh:1", "fix_state": "Affected", "package_name": "rhdh/rhdh-hub-rhel9", "product_name": "Red Hat Developer Hub"}, {"cpe": "cpe:/a:redhat:ansible_portal:2", "fix_state": "Affected", "package_name": "ansible-automation-platform/automation-portal", "product_name": "Self-service automation portal 2"}], "public_date": "2026-08-13T17:32:39Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-73563\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-73563\nhttps://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4"], "statement": "Red Hat Developer Hub (RHDH) and Ansible Automation Portal ship @backstage/plugin-auth-backend, which contains this vulnerability. However, the affected features (experimental dynamic client registration and client ID metadata documents) are disabled by default. Only deployments that have explicitly enabled these experimental features and configured custom wildcard-hostname or protocol-less patterns in their allowlists are vulnerable. Default RHDH configurations are not affected.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.29.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "backstage", "source": "cna", "vendor": "backstage"}, "product": "backstage", "vendor": "backstage"}], "created": "2026-08-13T18:45:04.203213+00:00", "updated": "2026-08-22T10:30:17.480044+00:00", "vendors": ["backstage", "backstage$PRODUCT$backstage"]}