CVE-2026-27738

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27738", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-02-23T18:37:14.790Z", "datePublished": "2026-02-25T16:40:44.724Z", "dateUpdated": "2026-02-27T20:46:26.917Z"}, "containers": {"cna": {"title": "Angular SSR has an Open Redirect via X-Forwarded-Prefix", "problemTypes": [{"descriptions": [{"cweId": "CWE-601", "lang": "en", "description": "CWE-601: URL Redirection to Untrusted Site ('Open Redirect')", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/angular/angular-cli/security/advisories/GHSA-xh43-g2fq-wjrj", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/angular/angular-cli/security/advisories/GHSA-xh43-g2fq-wjrj"}, {"name": "https://github.com/angular/angular-cli/issues/32501", "tags": ["x_refsource_MISC"], "url": "https://github.com/angular/angular-cli/issues/32501"}, {"name": "https://github.com/angular/angular-cli/pull/32521", "tags": ["x_refsource_MISC"], "url": "https://github.com/angular/angular-cli/pull/32521"}, {"name": "https://github.com/angular/angular-cli/commit/877f017ace4b83277d773aa37f5813e5e9faec7e", "tags": ["x_refsource_MISC"], "url": "https://github.com/angular/angular-cli/commit/877f017ace4b83277d773aa37f5813e5e9faec7e"}], "affected": [{"vendor": "angular", "product": "angular-cli", "versions": [{"version": ">= 21.2.0-next.2, < 21.2.0-rc.0", "status": "affected"}, {"version": ">= 21.0.0-next.0, < 21.1.5", "status": "affected"}, {"version": ">= 20.0.0-next.0, < 20.3.17", "status": "affected"}, {"version": ">= 19.0.0-next.0, < 19.2.21", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-02-25T16:40:44.724Z"}, "descriptions": [{"lang": "en", "value": "The Angular SSR is a server-rise rendering tool for Angular applications. An Open Redirect vulnerability exists in the internal URL processing logic in versions on the 19.x branch prior to 19.2.21, the 20.x branch prior to 20.3.17, and the 21.x branch prior to 21.1.5 and 21.2.0-rc.1. The logic normalizes URL segments by stripping leading slashes; however, it only removes a single leading slash. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker can provide a value starting with three slashes. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking. In order to be vulnerable, the application must use Angular SSR, the application must have routes that perform internal redirects, the infrastructure (Reverse Proxy/CDN) must pass the `X-Forwarded-Prefix` header to the SSR process without sanitization, and the cache must not vary on the `X-Forwarded-Prefix` header. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 contain a patch. Until the patch is applied, developers should sanitize the `X-Forwarded-Prefix` header in their`server.ts` before the Angular engine processes the request."}], "source": {"advisory": "GHSA-xh43-g2fq-wjrj", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/angular/angular-cli/issues/32501", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-02-27T20:46:21.327125Z", "id": "CVE-2026-27738", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"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": "2026-02-27T20:46:26.917Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-27738", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-02-27T20:46:21.327125Z"}}}], "references": [{"url": "https://github.com/angular/angular-cli/issues/32501", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-27T20:46:02.667Z"}}], "cna": {"title": "Angular SSR has an Open Redirect via X-Forwarded-Prefix", "source": {"advisory": "GHSA-xh43-g2fq-wjrj", "discovery": "UNKNOWN"}, "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 6.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "LOW", "vulnIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "vulnConfidentialityImpact": "NONE"}}], "affected": [{"vendor": "angular", "product": "angular-cli", "versions": [{"status": "affected", "version": ">= 21.2.0-next.2, < 21.2.0-rc.0"}, {"status": "affected", "version": ">= 21.0.0-next.0, < 21.1.5"}, {"status": "affected", "version": ">= 20.0.0-next.0, < 20.3.17"}, {"status": "affected", "version": ">= 19.0.0-next.0, < 19.2.21"}]}], "references": [{"url": "https://github.com/angular/angular-cli/security/advisories/GHSA-xh43-g2fq-wjrj", "name": "https://github.com/angular/angular-cli/security/advisories/GHSA-xh43-g2fq-wjrj", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/angular/angular-cli/issues/32501", "name": "https://github.com/angular/angular-cli/issues/32501", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/angular/angular-cli/pull/32521", "name": "https://github.com/angular/angular-cli/pull/32521", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/angular/angular-cli/commit/877f017ace4b83277d773aa37f5813e5e9faec7e", "name": "https://github.com/angular/angular-cli/commit/877f017ace4b83277d773aa37f5813e5e9faec7e", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "The Angular SSR is a server-rise rendering tool for Angular applications. An Open Redirect vulnerability exists in the internal URL processing logic in versions on the 19.x branch prior to 19.2.21, the 20.x branch prior to 20.3.17, and the 21.x branch prior to 21.1.5 and 21.2.0-rc.1. The logic normalizes URL segments by stripping leading slashes; however, it only removes a single leading slash. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker can provide a value starting with three slashes. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking. In order to be vulnerable, the application must use Angular SSR, the application must have routes that perform internal redirects, the infrastructure (Reverse Proxy/CDN) must pass the `X-Forwarded-Prefix` header to the SSR process without sanitization, and the cache must not vary on the `X-Forwarded-Prefix` header. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 contain a patch. Until the patch is applied, developers should sanitize the `X-Forwarded-Prefix` header in their`server.ts` before the Angular engine processes the request."}], "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": "2026-02-25T16:40:44.724Z"}}}, "cveMetadata": {"cveId": "CVE-2026-27738", "state": "PUBLISHED", "dateUpdated": "2026-02-27T20:46:26.917Z", "dateReserved": "2026-02-23T18:37:14.790Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-02-25T16:40:44.724Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "angular-cli", "vendor": "angular", "versions": [{"status": "affected", "version": ">= 21.2.0-next.2, < 21.2.0-rc.0"}, {"status": "affected", "version": ">= 21.0.0-next.0, < 21.1.5"}, {"status": "affected", "version": ">= 20.0.0-next.0, < 20.3.17"}, {"status": "affected", "version": ">= 19.0.0-next.0, < 19.2.21"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Angular SSR is a server-rise rendering tool for Angular applications. An Open Redirect vulnerability exists in the internal URL processing logic in versions on the 19.x branch prior to 19.2.21, the 20.x branch prior to 20.3.17, and the 21.x branch prior to 21.1.5 and 21.2.0-rc.1. The logic normalizes URL segments by stripping leading slashes; however, it only removes a single leading slash. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker can provide a value starting with three slashes. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking. In order to be vulnerable, the application must use Angular SSR, the application must have routes that perform internal redirects, the infrastructure (Reverse Proxy/CDN) must pass the `X-Forwarded-Prefix` header to the SSR process without sanitization, and the cache must not vary on the `X-Forwarded-Prefix` header. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 contain a patch. Until the patch is applied, developers should sanitize the `X-Forwarded-Prefix` header in their`server.ts` before the Angular engine processes the request."}, {"lang": "es", "value": "El Angular SSR es una herramienta de renderizado del lado del servidor para aplicaciones Angular. Una vulnerabilidad de redirecci\u00f3n abierta existe en la l\u00f3gica interna de procesamiento de URL en versiones de la rama 19.x anteriores a la 19.2.21, la rama 20.x anteriores a la 20.3.17, y la rama 21.x anteriores a la 21.1.5 y 21.2.0-rc.1. La l\u00f3gica normaliza los segmentos de URL eliminando las barras iniciales; sin embargo, solo elimina una \u00fanica barra inicial. Cuando una aplicaci\u00f3n Angular SSR se despliega detr\u00e1s de un proxy que pasa el encabezado `X-Forwarded-Prefix`, un atacante puede proporcionar un valor que comienza con tres barras. Esta vulnerabilidad permite a los atacantes realizar phishing a gran escala y secuestro de SEO. Para ser vulnerable, la aplicaci\u00f3n debe usar Angular SSR, la aplicaci\u00f3n debe tener rutas que realicen redirecciones internas, la infraestructura (Proxy Inverso/CDN) debe pasar el encabezado `X-Forwarded-Prefix` al proceso SSR sin sanitizaci\u00f3n, y la cach\u00e9 no debe variar seg\u00fan el encabezado `X-Forwarded-Prefix`. Las versiones 21.2.0-rc.1, 21.1.5, 20.3.17 y 19.2.21 contienen un parche. Hasta que se aplique el parche, los desarrolladores deben sanear el encabezado `X-Forwarded-Prefix` en su 'server.ts' antes de que el motor de Angular procese la solicitud."}], "id": "CVE-2026-27738", "lastModified": "2026-06-17T10:27:36.323", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-27738", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-02-27T20:46:21.327125Z", "version": "2.0.3"}}]}, "published": "2026-02-25T17:25:40.463", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/angular/angular-cli/commit/877f017ace4b83277d773aa37f5813e5e9faec7e"}, {"source": "security-advisories@github.com", "url": "https://github.com/angular/angular-cli/issues/32501"}, {"source": "security-advisories@github.com", "url": "https://github.com/angular/angular-cli/pull/32521"}, {"source": "security-advisories@github.com", "url": "https://github.com/angular/angular-cli/security/advisories/GHSA-xh43-g2fq-wjrj"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/angular/angular-cli/issues/32501"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-601"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[21.2.0-next.2,21.2.0-rc.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[21.0.0-next.0,21.1.5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[20.0.0-next.0,20.3.17)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[19.0.0-next.0,19.2.21)"}}], "enrichment": {"confidence": 88.0, "confidence_source": "matching", "scores": [{"score": 88.0, "source": "matching"}]}, "original": {"product": "angular-cli", "source": "cna", "vendor": "angular"}, "product": "angular", "vendor": "angular"}], "analysis": {"en": {"generated_at": "2026-04-18T10:39:56.321969+00:00", "value": {"mitigation_remediation": ["Update Angular CLI to a patched release (19.2.21, 20.3.17, 21.1.5, or later 21.2.0\u2011rc.1).", "If an update cannot be applied immediately, sanitize the X\u2011Forwarded\u2011Prefix header in server.ts before the Angular engine processes the request.", "Ensure that the application\u2019s caching layer varies on the X\u2011Forwarded\u2011Prefix header to prevent cached redirects from affecting other requests."], "summary": {"action": "Apply Patch", "impact": "Open Redirect enabling phishing and SEO hijacking"}, "threat_synthesis": {"affected_systems": "The weakness affects Angular CLI projects on the 19.x branch before version 19.2.21, the 20.x branch before version 20.3.17, and the 21.x branch before 21.1.5 and 21.2.0\u2011rc.1. Any deployment that processes the X\u2011Forwarded\u2011Prefix header without sanitization and whose cache does not vary on that header is vulnerable.", "description_and_impact": "An open redirect flaw exists in Angular SSR\u2019s URL processing logic. The code removes only a single leading slash from URL segments, allowing an attacker to send a value that starts with three slashes via the X\u2011Forwarded\u2011Prefix header when the application runs behind a proxy. The result is that internal routing can redirect users to arbitrary sites, facilitating large\u2011scale phishing or search\u2011engine hijacking. This is a classic CWE\u2011601 vulnerability with a CVSS score of 6.9, indicating a moderate severity.", "risk_and_exploitability": "The exploitation probability is very low, with the risk metric indicating less than a 1% likelihood of exploitation. The vulnerability is not identified in CISA\u2019s catalog of known exploited vulnerabilities. The most likely attack vector is remote, with an adversary able to influence the X\u2011Forwarded\u2011Prefix header through a compromised or malicious reverse proxy or CDN. While the chance of exploitation remains modest, the potential impact on user safety and brand reputation remains significant."}}}}, "created": "2026-02-26T13:15:19.895160+00:00", "updated": "2026-04-18T10:45:43.660906+00:00", "vendors": ["angular", "angular$PRODUCT$angular"]}