CVE-2026-41423: Angular SSRF Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-45q2-gjvg-7973",
  "modified" : "2026-05-12T13:31:29Z",
  "published" : "2026-04-16T22:36:01Z",
  "aliases" : [ "CVE-2026-41423" ],
  "summary" : "Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server",
  "details" : "### Impact\n\nA [Server-Side Request Forgery (SSRF)](https://developer.mozilla.org/en-US/docs/Web/Security/Attacks/SSRF) vulnerability exists in `@angular/platform-server` due to improper handling of URLs during Server-Side Rendering (SSR).\n\nWhen an attacker sends a request such as `GET /\\evil.com/ HTTP/1.1` the server engine (Express, etc.) passes the URL string to Angular’s rendering functions.\n\nBecause the URL parser normalizes the backslash to a forward slash for HTTP/HTTPS schemes, the internal state of the application is hijacked to believe the current origin is `evil.com`. This misinterpretation tricks the application into treating the attacker’s domain as the local origin. Consequently, any relative `HttpClient` requests or `PlatformLocation.hostname` references are redirected to the attacker controlled server, potentially exposing internal APIs or metadata services.\n\n**Affected APIs:**\n- `renderModule`\n- `renderApplication`\n- `CommonEngine` (from `@angular/ssr`)\n\n**Non-Affected APIs:**\n- `AngularAppEngine` (from `@angular/ssr`)\n- `AngularNodeAppEngine` (from `@angular/ssr`)\n\n### Attack Preconditions\n- The server has outbound network access.\n- The application uses Angular SSR via the affected APIs.\n- A pathname is passed as URL to the rendering method  (e.g. using `req.url`).\n- The server-side code performs HTTP requests using `HttpClient` with relative URLs or uses `PlatformLocation.hostname` to build URLs. \n\n\n### Patches\n- 22.0.0-next.8\n- 21.2.9\n- 20.3.19\n- 19.2.21\n\n### Workarounds\nDevelopers should implement a middleware to sanitize the request URL before it reaches Angular. This involves stripping or normalizing leading slashes:\n\n```js\napp.use((req, res, next) => {\n  // Sanitize the URL to ensure it starts with a single forward slash\n  if (req.url.startsWith('//') || req.url.startsWith('/\\\\') || req.url.startsWith('\\\\')) {\n     req.url = '/' + req.url.replace(/^[/\\\\]+/, '');\n  }\n  next();\n});\n\n```\n### References\n- [Fix](https://github.com/angular/angular/pull/68194)",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@angular/platform-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "22.0.0-next.0"
      }, {
        "fixed" : "22.0.0-next.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@angular/platform-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "21.0.0-next.0"
      }, {
        "fixed" : "21.2.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@angular/platform-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "20.0.0-next.0"
      }, {
        "fixed" : "20.3.19"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@angular/platform-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "19.0.0-next.0"
      }, {
        "fixed" : "19.2.21"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@angular/platform-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "18.2.14"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/angular/angular/security/advisories/GHSA-45q2-gjvg-7973"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41423"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/angular/angular/pull/68194"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/angular/angular/commit/ede7c58a2aa13fdccc8f0b67ce93ba1c11749412"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/angular/angular"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-16T22:36:01Z",
    "nvd_published_at" : "2026-05-08T14:16:33Z"
  }
}