{"cve":{"cve_id":"CVE-2026-33397","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00255,"epss_percentile":0.16663,"epss_as_of":"2026-06-23","description":"The Angular SSR is a server-rise rendering tool for Angular applications. Versions on the 22.x branch prior to 22.0.0-next.2, the 21.x branch prior to 21.2.3, and the 20.x branch prior to 20.3.21 have an Open Redirect vulnerability in `@angular/ssr` due to an incomplete fix for CVE-2026-27738. While the original fix successfully blocked multiple leading slashes (e.g., `///`), the internal validation logic fails to account for a single backslash (`\\`) bypass. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker provides a value starting with a single backslash, the internal validation failed to flag the single backslash as invalid, the application prepends a leading forward slash, resulting in a `Location` header containing the URL, and modern browsers interpret the `/\\` sequence as `//`, treating it as a protocol-relative URL and redirecting the user to the attacker-controlled domain. Furthermore, the response lacks the `Vary: X-Forwarded-Prefix` header, allowing the malicious redirect to be stored in intermediate caches (Web Cache Poisoning). Versions 22.0.0-next.2, 21.2.3, and 20.3.21 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.","published_at":"2026-03-26T13:46:16.145000Z","last_modified_at":null,"cvss_v3_score":null,"cvss_v3_vector":null,"cvss_v3_severity":null,"cvss_v4_score":6.9,"cvss_v4_vector":"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","cvss_v4_severity":"MEDIUM","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-601"],"nvd_references":["https://github.com/angular/angular-cli/security/advisories/GHSA-vfx2-hv2g-xj5f","https://github.com/angular/angular-cli/pull/32771","https://github.com/advisories/GHSA-xh43-g2fq-wjrj"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:29:53.836916Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":null,"metrics":[]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"N","value_label":"None"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"N","value_label":"None"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"L","value_label":"Low"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"L","value_label":"Low"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"}]},"affected":[{"vendor_slug":"angular","vendor_name":"angular","product_slug":"angular-cli","product_name":"angular-cli","version_start":">= 22.0.0-next.0, < 22.0.0-next.2","version_start_inclusive":true,"version_end":">= 22.0.0-next.0, < 22.0.0-next.2","version_end_inclusive":true,"cpe23_uri":"cve5:angular:angular-cli:>= 22.0.0-next.0, < 22.0.0-next.2:>= 22.0.0-next.0, < 22.0.0-next.2"},{"vendor_slug":"angular","vendor_name":"angular","product_slug":"angular-cli","product_name":"angular-cli","version_start":">= 21.0.0-next.0, < 21.2.3","version_start_inclusive":true,"version_end":">= 21.0.0-next.0, < 21.2.3","version_end_inclusive":true,"cpe23_uri":"cve5:angular:angular-cli:>= 21.0.0-next.0, < 21.2.3:>= 21.0.0-next.0, < 21.2.3"},{"vendor_slug":"angular","vendor_name":"angular","product_slug":"angular-cli","product_name":"angular-cli","version_start":">= 20.0.0-next.0, < 20.3.21","version_start_inclusive":true,"version_end":">= 20.0.0-next.0, < 20.3.21","version_end_inclusive":true,"cpe23_uri":"cve5:angular:angular-cli:>= 20.0.0-next.0, < 20.3.21:>= 20.0.0-next.0, < 20.3.21"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/angular/angular-cli/security/advisories/GHSA-vfx2-hv2g-xj5f","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/angular/angular-cli/pull/32771","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/advisories/GHSA-xh43-g2fq-wjrj","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-03-26T13:46:16.145000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:53:15.351162Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:53:15.351162Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:53:15.351162Z","label":"CVSS score revised","source":"cvelistv5"}]}