Understanding CVE-2025-59052: What Angular Users Need to Know

Angular has long been known as one of the most stable and reliable frontend frameworks. However, a recent security advisory, CVE-2025-59052, highlights a significant vulnerability in certain versions of Angular that support Server-Side Rendering (SSR). This post explains CVE-2025-59052, its impact on Angular SSR applications, the risks of using affected versions, and recommended actions to protect your users.

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What is CVE-2025-59052?

CVE-2025-59052 is a race condition vulnerability in Angular's SSR system that can lead to cross-request data leakage. A race condition occurs when multiple processes try to access and modify shared data at the same time, which can cause unpredictable or incorrect behavior.

In this case, the problem comes from Angular’s platform injector, which manages user- and request-specific state during SSR. In affected versions, the platform injector was implemented as a global variable, meaning that concurrent requests to render pages on the server could interfere with each other.

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How This Affects Angular Applications

For applications using SSR, this vulnerability creates the possibility that data from one user’s session could be accidentally exposed to another user. The type of data that could leak depends on what your server-side code passes through Angular’s rendering pipeline, which may include:

• Personalized content (e.g., user dashboards)
• Authentication tokens or session data
• Any other per-request context used in rendering

Although the leak only occurs under concurrent requests, in a production environment handling multiple users at the same time, this can be a significant risk.

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Consequences of Using Affected Versions

Vulnerable Angular SSR applications can expose user data to other users, which could include authentication tokens, personalized content, or other sensitive per-request information.

For organizations handling regulated or sensitive data, such as personal or financial information, this creates compliance risks, because exposing user data could violate legal requirements. Beyond regulatory concerns, any data leakage can lead to reputational damage if users’ private information is inadvertently shared.

Unsupported Angular versions are particularly risky because no official patch exists, leaving these vulnerabilities unmitigated unless third-party support, such as HeroDevs, is used.

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Recommended Actions

1. Upgrade to supported versions of Angular
   Angular has released security patches that fix this issue. Upgrading ensures your application is protected.
   
   
2. If you’re on an unsupported version
   HeroDevs provides patches for end-of-life Angular versions, allowing customers to mitigate this vulnerability even when official support has ended.
   
   
3. Temporary mitigations
   
   • Disabling SSR where possible until an upgrade is applied.
   • Avoid asynchronous initialization during server-side rendering.
   • Remove any uses of getPlatform() in server-side code.
   • Ensure the server build sets ngJitMode to false.

Conclusion

CVE-2025-59052 is a serious vulnerability affecting Angular applications using SSR, with the potential for cross-user data leaks. Supported versions of Angular now include security patches to fix this issue. For organizations using unsupported versions, HeroDevs provides patches and long-term support to protect customer applications.