@angular/platform-server: Open Redirect via Protocol-Relative URLs in Server-Side Rendering (SSR)

{
  "id": "65cc97022647007b0d846e84d50729ae2611f518c0ea49c6e472af6653e19828",
  "url": "https://osv.dev/vulnerability/GHSA-w739-gvwx-grc3",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "@angular/platform-server: Open Redirect via Protocol-Relative URLs in Server-Side Rendering (SSR)",
    "summary": "An open redirect vulnerability was identified in `@angular/platform-server` when Server-Side Rendering (SSR) is enabled. When Angular SSR renders an incoming request, URL resolution and platform navigation are managed by `ServerPlatformLocation` using `resolveUrl` (or `parseUrl` in v20). While `resolveUrl` rejected protocol-relative URLs whose raw string directly started with `//`, this check ran *prior* to WHATWG URL normalization. When a request URL includes a popping dot-segment followed by multiple slashes (such as `/.//evil.test` or serialized from router route shapes like `/.;/(//evil.test)`), the input bypassed the initial `urlStr.startsWith('//')` check. Subsequent WHATWG URL parsing resolved the dot-segments and resulted in a `pathname` starting with `//` (`//evil.test`). Consequently, `ServerPlatformLocation` stored `pathname = '//evil.test'`. When `@angular/ssr` detected a mismatch between the rendered URL and the router's final location state, it emitted the unnormalized pathname into the HTTP `Location` response header, producing an HTTP 302 redirect with `Location: //evil.test`, which browsers resolve as a protocol-relative navigation off-origin. ### Impact Successful exploitation allows an unauthenticated remote attacker to craft URLs that trick Angular SSR into redirecting users to an arbitrary external domain. * **Bypasses Application-Level Guards:** Common application-level validation routines (such as checking `!returnUrl.startsWith('//')` before invoking `",
    "evidence": "osv:GHSA-w739-gvwx-grc3",
    "products": [
      {
        "name": {
          "value": "@angular/platform-server",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "22.2.1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "@angular/platform-server",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "21.2.25",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "@angular/platform-server",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "20.3.33",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "@angular/platform-server",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-w739-gvwx-grc3",
      "aliases": [
        "CVE-2026-111754",
        "GHSA-w739-gvwx-grc3"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "22.0.0"
                },
                {
                  "fixed": "22.2.1"
                }
              ]
            }
          ],
          "package": {
            "name": "@angular/platform-server",
            "purl": "pkg:npm/%40angular/platform-server",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-w739-gvwx-grc3/GHSA-w739-gvwx-grc3.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "21.0.0"
                },
                {
                  "fixed": "21.2.25"
                }
              ]
            }
          ],
          "package": {
            "name": "@angular/platform-server",
            "purl": "pkg:npm/%40angular/platform-server",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-w739-gvwx-grc3/GHSA-w739-gvwx-grc3.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "20.0.0"
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                {
                  "fixed": "20.3.33"
                }
              ]
            }
          ],
          "package": {
            "name": "@angular/platform-server",
            "purl": "pkg:npm/%40angular/platform-server",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-w739-gvwx-grc3/GHSA-w739-gvwx-grc3.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "19.2.25"
                }
              ]
            }
          ],
          "package": {
            "name": "@angular/platform-server",
            "purl": "pkg:npm/%40angular/platform-server",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-w739-gvwx-grc3/GHSA-w739-gvwx-grc3.json"
          }
        }
      ],
      "modified": "2026-10-20T14:45:03.771349618Z",
      "provider": "osv",
      "references": [
        "https://github.com/angular/angular/security/advisories/GHSA-w739-gvwx-grc3",
        "https://github.com/angular/angular/pull/71077",
        "https://github.com/angular/angular/pull/71078",
        "https://github.com/angular/angular/pull/71079",
        "https://github.com/angular/angular/commit/450af9c813c7660b9bd91e5635f705ee3ed7b32a",
        "https://github.com/angular/angular/commit/83944fc8c50e86be90e8ec4184cd15002b5af262",
        "https://github.com/angular/angular/commit/928dcfd2582152655b5559509d057bf6a5a19521",
        "https://github.com/angular/angular/commit/d7d81e189d227108c3b9d39178dbb7389f6f970d",
        "https://github.com/angular/angular",
        "https://github.com/angular/angular/releases/tag/v20.3.33",
        "https://github.com/angular/angular/releases/tag/v21.2.25",
        "https://github.com/angular/angular/releases/tag/v22.2.1"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-601"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-20T14:35:49Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111754",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 389728,
  "published_at": "2026-10-20T14:35:49+00:00"
}