angular angular-cli up to 19.2.20/20.3.16/21.1.4 URL redirect

Summaryinfo

A vulnerability was found in angular angular-cli up to 19.2.20/20.3.16/21.1.4 and classified as problematic. Affected by this vulnerability is an unknown functionality of the component URL Handler. The manipulation results in redirect. This vulnerability is known as CVE-2026-27738. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in angular angular-cli up to 19.2.20/20.3.16/21.1.4. It has been classified as problematic. Affected is an unknown code of the component URL Handler. The manipulation with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on confidentiality, and integrity. CVE summarizes:

The Angular SSR is a server-rise rendering tool for Angular applications. An Open Redirect vulnerability exists in the internal URL processing logic in versions on the 19.x branch prior to 19.2.21, the 20.x branch prior to 20.3.17, and the 21.x branch prior to 21.1.5 and 21.2.0-rc.1. The logic normalizes URL segments by stripping leading slashes; however, it only removes a single leading slash. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker can provide a value starting with three slashes. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking. In order to be vulnerable, the application must use Angular SSR, the application must have routes that perform internal redirects, the infrastructure (Reverse Proxy/CDN) must pass the `X-Forwarded-Prefix` header to the SSR process without sanitization, and the cache must not vary on the `X-Forwarded-Prefix` header. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-27738 since 02/23/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1204.001.

Upgrading to version 19.2.21, 20.3.17, 21.1.5 or 21.2.0-rc.0 eliminates this vulnerability. Applying the patch 877f017ace4b83277d773aa37f5813e5e9faec7e is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0534). Once again VulDB remains the best source for vulnerability data.

Affected

• Open Source Angular

Productinfo

Type

• JavaScript Library

Vendor

• angular

Name

• angular-cli

Version

• 19.2.0
• 19.2.1
• 19.2.2
• 19.2.3
• 19.2.4
• 19.2.5
• 19.2.6
• 19.2.7
• 19.2.8
• 19.2.9
• 19.2.10
• 19.2.11
• 19.2.12
• 19.2.13
• 19.2.14
• 19.2.15
• 19.2.16
• 19.2.17
• 19.2.18
• 19.2.19
• 19.2.20
• 20.3.0
• 20.3.1
• 20.3.2
• 20.3.3
• 20.3.4
• 20.3.5
• 20.3.6
• 20.3.7
• 20.3.8
• 20.3.9
• 20.3.10
• 20.3.11
• 20.3.12
• 20.3.13
• 20.3.14
• 20.3.15
• 20.3.16
• 21.1.0
• 21.1.1
• 21.1.2
• 21.1.3
• 21.1.4

License

• open-source

Website

• Product: https://github.com/angular/angular-cli/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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