VYPR
Medium severity5.3GHSA Advisory· Published May 8, 2026· Updated May 12, 2026

CVE-2026-41423

CVE-2026-41423

Description

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8, a Server-Side Request Forgery (SSRF) vulnerability exists in @angular/platform-server due to improper handling of URLs during Server-Side Rendering (SSR). When 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. Because 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. This issue has been patched in versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
@angular/platform-servernpm
>= 22.0.0-next.0, < 22.0.0-next.822.0.0-next.8
@angular/platform-servernpm
>= 21.0.0-next.0, < 21.2.921.2.9
@angular/platform-servernpm
>= 20.0.0-next.0, < 20.3.1920.3.19
@angular/platform-servernpm
>= 19.0.0-next.0, < 19.2.2119.2.21
@angular/platform-servernpm
<= 18.2.14

Affected products

1

Patches

1
ede7c58a2aa1

fix(platform-server): prevent SSRF bypasses via protocol-relative and backslash URLs

https://github.com/angular/angularAlan AgiusApr 14, 2026via ghsa
2 files changed · +72 145
  • packages/platform-server/src/location.ts+30 37 modified
    @@ -18,29 +18,18 @@ import {Subject} from 'rxjs';
     
     import {INITIAL_CONFIG} from './tokens';
     
    -function parseUrl(
    -  urlStr: string,
    -  origin: string,
    -): {
    -  hostname: string;
    -  protocol: string;
    -  port: string;
    -  pathname: string;
    -  search: string;
    -  hash: string;
    -  href: string;
    -} {
    -  const {hostname, protocol, port, pathname, search, hash, href} = new URL(urlStr, origin);
    -
    -  return {
    -    hostname,
    -    href,
    -    protocol,
    -    port,
    -    pathname,
    -    search,
    -    hash,
    -  };
    +/**
    + * Parses a URL string and returns a URL object.
    + * @param urlStr The string to parse.
    + * @param origin The origin to use for resolving the URL.
    + * @returns The parsed URL.
    + */
    +function parseUrl(urlStr: string, origin: string): URL {
    +  // If the URL is empty or start with a `/` it is a pathname relative to the origin
    +  // otherwise it's an absolute URL.
    +  const urlToParse = urlStr.length === 0 || urlStr[0] === '/' ? origin + urlStr : urlStr;
    +
    +  return new URL(urlToParse);
     }
     
     /**
    @@ -65,14 +54,17 @@ export class ServerPlatformLocation implements PlatformLocation {
           return;
         }
         if (config.url) {
    -      const url = parseUrl(config.url, this._doc.location.origin);
    -      this.protocol = url.protocol;
    -      this.hostname = url.hostname;
    -      this.port = url.port;
    -      this.pathname = url.pathname;
    -      this.search = url.search;
    -      this.hash = url.hash;
    -      this.href = url.href;
    +      const {protocol, hostname, port, pathname, search, hash, href} = parseUrl(
    +        config.url,
    +        this._doc.location.origin,
    +      );
    +      this.protocol = protocol;
    +      this.hostname = hostname;
    +      this.port = port;
    +      this.pathname = pathname;
    +      this.search = search;
    +      this.hash = hash;
    +      this.href = href;
         }
       }
     
    @@ -114,12 +106,13 @@ export class ServerPlatformLocation implements PlatformLocation {
     
       replaceState(state: any, title: string, newUrl: string): void {
         const oldUrl = this.url;
    -    const parsedUrl = parseUrl(newUrl, this._doc.location.origin);
    -    (this as Writable<this>).pathname = parsedUrl.pathname;
    -    (this as Writable<this>).search = parsedUrl.search;
    -    (this as Writable<this>).href = parsedUrl.href;
    -    (this as Writable<this>).protocol = parsedUrl.protocol;
    -    this.setHash(parsedUrl.hash, oldUrl);
    +    const {pathname, search, hash, href, protocol} = parseUrl(newUrl, this._doc.location.origin);
    +    const writableThis = this as Writable<this>;
    +    writableThis.pathname = pathname;
    +    writableThis.search = search;
    +    writableThis.href = href;
    +    writableThis.protocol = protocol;
    +    this.setHash(hash, oldUrl);
       }
     
       pushState(state: any, title: string, newUrl: string): void {
    
  • packages/platform-server/test/platform_location_spec.ts+42 108 modified
    @@ -8,20 +8,13 @@
     import '@angular/compiler';
     
     import {PlatformLocation, ɵgetDOM as getDOM} from '@angular/common';
    -import {Component, destroyPlatform} from '@angular/core';
    +import {destroyPlatform} from '@angular/core';
     import {INITIAL_CONFIG, platformServer} from '@angular/platform-server';
    -import {bootstrapApplication} from '@angular/platform-browser';
     
     (function () {
       if (getDOM().supportsDOMEvents) return; // NODE only
     
       describe('PlatformLocation', () => {
    -    @Component({
    -      selector: 'app',
    -      template: `Works!`,
    -    })
    -    class LocationApp {}
    -
         beforeEach(() => {
           destroyPlatform();
         });
    @@ -34,15 +27,8 @@ import {bootstrapApplication} from '@angular/platform-browser';
           const platform = platformServer([
             {provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}},
           ]);
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [{provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}}],
    -        },
    -        {platformRef: platform},
    -      );
     
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           expect(location.pathname).toBe('/');
           platform.destroy();
         });
    @@ -57,23 +43,7 @@ import {bootstrapApplication} from '@angular/platform-browser';
             },
           ]);
     
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [
    -            {
    -              provide: INITIAL_CONFIG,
    -              useValue: {
    -                document: '<app></app>',
    -                url: 'http://test.com/deep/path?query#hash',
    -              },
    -            },
    -          ],
    -        },
    -        {platformRef: platform},
    -      );
    -
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           expect(location.pathname).toBe('/deep/path');
           expect(location.search).toBe('?query');
           expect(location.hash).toBe('#hash');
    @@ -90,23 +60,7 @@ import {bootstrapApplication} from '@angular/platform-browser';
             },
           ]);
     
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [
    -            {
    -              provide: INITIAL_CONFIG,
    -              useValue: {
    -                document: '<app></app>',
    -                url: 'http://test.com:80/deep/path?query#hash',
    -              },
    -            },
    -          ],
    -        },
    -        {platformRef: platform},
    -      );
    -
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           expect(location.hostname).toBe('test.com');
           expect(location.protocol).toBe('http:');
           expect(location.port).toBe('');
    @@ -126,23 +80,7 @@ import {bootstrapApplication} from '@angular/platform-browser';
             },
           ]);
     
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [
    -            {
    -              provide: INITIAL_CONFIG,
    -              useValue: {
    -                document: '<app></app>',
    -                url: 'http://test.com/deep/path',
    -              },
    -            },
    -          ],
    -        },
    -        {platformRef: platform},
    -      );
    -
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           expect(location.pathname).toBe('/deep/path');
           expect(location.search).toBe('');
           expect(location.hash).toBe('');
    @@ -153,14 +91,7 @@ import {bootstrapApplication} from '@angular/platform-browser';
             {provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}},
           ]);
     
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [{provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}}],
    -        },
    -        {platformRef: platform},
    -      );
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           location.pushState(null, 'Test', '/foo#bar');
           expect(location.pathname).toBe('/foo');
           expect(location.hash).toBe('#bar');
    @@ -178,22 +109,7 @@ import {bootstrapApplication} from '@angular/platform-browser';
             },
           ]);
     
    -      const appRef = await bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [
    -            {
    -              provide: INITIAL_CONFIG,
    -              useValue: {
    -                document: '<app></app>',
    -                url: 'http://test.com/deep/path?query#hash',
    -              },
    -            },
    -          ],
    -        },
    -        {platformRef: platform},
    -      );
    -      const location = appRef.injector.get(PlatformLocation);
    +      const location = platform.injector.get(PlatformLocation);
           location.replaceState(null, 'Test', '/foo#bar');
           expect(location.pathname).toBe('/foo');
           expect(location.hash).toBe('#bar');
    @@ -206,24 +122,42 @@ import {bootstrapApplication} from '@angular/platform-browser';
           const platform = platformServer([
             {provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}},
           ]);
    -      bootstrapApplication(
    -        LocationApp,
    -        {
    -          providers: [{provide: INITIAL_CONFIG, useValue: {document: '<app></app>'}}],
    -        },
    -        {platformRef: platform},
    -      ).then((appRef) => {
    -        const location: PlatformLocation = appRef.injector.get(PlatformLocation);
    -        expect(location.pathname).toBe('/');
    -        location.onHashChange((e: any) => {
    -          expect(e.type).toBe('hashchange');
    -          expect(e.oldUrl).toBe('/');
    -          expect(e.newUrl).toBe('/foo#bar');
    -          platform.destroy();
    -          done();
    -        });
    -        location.pushState(null, 'Test', '/foo#bar');
    +      const location = platform.injector.get(PlatformLocation);
    +
    +      expect(location.pathname).toBe('/');
    +      location.onHashChange((e: any) => {
    +        expect(e.type).toBe('hashchange');
    +        expect(e.oldUrl).toBe('/');
    +        expect(e.newUrl).toBe('/foo#bar');
    +        platform.destroy();
    +        done();
           });
    +      location.pushState(null, 'Test', '/foo#bar');
    +    });
    +
    +    it('neutralizes hostname hijack attempts', async () => {
    +      const urls = ['/\\attacker.com/deep/path', '//attacker.com/deep/path'];
    +
    +      for (const url of urls) {
    +        const platform = platformServer([
    +          {
    +            provide: INITIAL_CONFIG,
    +            useValue: {
    +              document: '',
    +              // This should be treated as relative URL.
    +              // Example: `req.url: '//attacker.com/deep/path'` where request
    +              // to express server is 'http://localhost:4200//attacker.com/deep/path'.
    +              url,
    +            },
    +          },
    +        ]);
    +
    +        const location = platform.injector.get(PlatformLocation);
    +        platform.destroy();
    +
    +        expect(location.hostname).withContext(`hostname for URL: "${url}"`).toBe('');
    +        expect(location.pathname).withContext(`pathname for URL: "${url}"`).toBe(url);
    +      }
         });
       });
     })();
    

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

5

News mentions

1