{"id":"CVE-2026-104871","state":"PUBLISHED","title":"Angular SSR: Path Traversal to Sibling Directories in CommonEngine on Windows","description":"The Angular SSR is a server-rise rendering tool for Angular applications. Prior to versions 20.3.36, 21.2.23, and 22.1.7, the CommonEngine retrieveSSGPage prerendered-page retrieval logic in @angular/ssr/node, and in @angular/ssr for versions 17 through 18, accepts a relative request URL containing a backslash parent-traversal segment on Windows. The non-special resolve:// URL base preserves the backslash, path.join interprets it as a Windows separator, and the pagePath.startsWith(normalize(publicPath)) check incorrectly accepts a sibling output directory whose name shares the configured public-directory prefix. An unauthenticated requester can therefore retrieve a sibling prerendered HTML page when that page contains the Angular SSG marker. The issue is limited to Windows deployments that pass relative request URLs to CommonEngine.render, have a prefix-sharing sibling output directory, and contain qualifying prerendered Angular HTML; it does not provide arbitrary file read. This issue is fixed in versions 20.3.36, 21.2.23, and 22.1.7.","publishedAt":"2026-10-02T19:43:50.475Z","updatedAt":"2026-10-02T20:12:49.364Z","severity":{"score":6.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["angular angular-cli"],"affected":[{"vendor":"angular","product":"angular-cli","versions":[{"version":"< 20.3.36","status":"affected"},{"version":">= 21.0.0, < 21.2.23","status":"affected"},{"version":">= 22.0.0, < 22.1.7","status":"affected"}]}],"references":["https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q","https://github.com/angular/angular-cli/commit/645e41a47d21b7651837a4250de99af0509626e2","https://github.com/angular/angular-cli/commit/70748ca8e76fe4b42798719410336119d943e755","https://github.com/angular/angular-cli/commit/bb72145f9ab45aee29f523236b3a25cd0813a841","https://github.com/angular/angular-cli/commit/c3e5982e49705f0f6a913cb94622b4c555d2d914","https://github.com/angular/angular-cli/releases/tag/v20.3.36","https://github.com/angular/angular-cli/releases/tag/v21.2.23","https://github.com/angular/angular-cli/releases/tag/v22.1.7"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/104xxx/CVE-2026-104871.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-104871","state":"PUBLISHED","datePublished":"2026-10-02T19:43:50.475Z","dateUpdated":"2026-10-02T20:12:49.364Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-02T14:59:11.775Z"},"containers":{"cna":{"title":"Angular SSR: Path Traversal to Sibling Directories in CommonEngine on Windows","descriptions":[{"lang":"en","value":"The Angular SSR is a server-rise rendering tool for Angular applications. Prior to versions 20.3.36, 21.2.23, and 22.1.7, the CommonEngine retrieveSSGPage prerendered-page retrieval logic in @angular/ssr/node, and in @angular/ssr for versions 17 through 18, accepts a relative request URL containing a backslash parent-traversal segment on Windows. The non-special resolve:// URL base preserves the backslash, path.join interprets it as a Windows separator, and the pagePath.startsWith(normalize(publicPath)) check incorrectly accepts a sibling output directory whose name shares the configured public-directory prefix. An unauthenticated requester can therefore retrieve a sibling prerendered HTML page when that page contains the Angular SSG marker. The issue is limited to Windows deployments that pass relative request URLs to CommonEngine.render, have a prefix-sharing sibling output directory, and contain qualifying prerendered Angular HTML; it does not provide arbitrary file read. This issue is fixed in versions 20.3.36, 21.2.23, and 22.1.7."}],"affected":[{"vendor":"angular","product":"angular-cli","versions":[{"version":"< 20.3.36","status":"affected"},{"version":">= 21.0.0, < 21.2.23","status":"affected"},{"version":">= 22.0.0, < 22.1.7","status":"affected"}]}],"references":[{"url":"https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q","name":"https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/angular/angular-cli/commit/645e41a47d21b7651837a4250de99af0509626e2","name":"https://github.com/angular/angular-cli/commit/645e41a47d21b7651837a4250de99af0509626e2","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/commit/70748ca8e76fe4b42798719410336119d943e755","name":"https://github.com/angular/angular-cli/commit/70748ca8e76fe4b42798719410336119d943e755","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/commit/bb72145f9ab45aee29f523236b3a25cd0813a841","name":"https://github.com/angular/angular-cli/commit/bb72145f9ab45aee29f523236b3a25cd0813a841","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/commit/c3e5982e49705f0f6a913cb94622b4c555d2d914","name":"https://github.com/angular/angular-cli/commit/c3e5982e49705f0f6a913cb94622b4c555d2d914","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/releases/tag/v20.3.36","name":"https://github.com/angular/angular-cli/releases/tag/v20.3.36","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/releases/tag/v21.2.23","name":"https://github.com/angular/angular-cli/releases/tag/v21.2.23","tags":["x_refsource_MISC"]},{"url":"https://github.com/angular/angular-cli/releases/tag/v22.1.7","name":"https://github.com/angular/angular-cli/releases/tag/v22.1.7","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-02T19:43:50.475Z"},"source":{"advisory":"GHSA-7g7c-h8rr-7p6q","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-02T20:12:27.563771Z","id":"CVE-2026-104871","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":"2026-10-02T20:12:49.364Z"}}]}}}