This vulnerability allows
for a Stored Cross-Site Scripting (XSS) attack in Angular, a development platform used for building mobile and desktop web applications. The vulnerability, identified as CVE-2025-66412, has a CVSS score of 8.5, categorizing it as high severity. This matter is critical as it poses a substantial risk to web applications built using this technology.
The XSS vulnerability occurs in the Angular Template Compiler, specifically due to an incomplete internal security schema. Attackers may leverage this flaw to bypass Angular's built-in security sanitization, leading to potential injection of malicious scripts. The urgency for defenders is evident; organizations should prioritize patching immediately.
The vulnerability affects versions prior to 21.0.2, 20.3.15, and 19.2.17. Although there is no known exploitation at this time, the high exploitability score indicates that it should not be overlooked. Organizations utilizing Angular should address this issue in their priority patch cycle.
Given the critical nature of this vulnerability, web applications using Angular must be updated to the patched versions to ensure security against potential XSS attacks.
Vulnerability Details
CVE-2025-66412 is classified as a Stored Cross-Site Scripting (XSS) vulnerability affecting the Angular Template Compiler. The CVSS score for this vulnerability is 8.5, indicating a high severity level. The vulnerability exists due to the compiler's internal security schema being incomplete, which allows attackers to bypass Angular's built-in security sanitization mechanisms. Specifically, certain URL-holding attributes are not classified as requiring strict URL security, resulting in the potential injection of malicious scripts.
The affected products include Angular versions prior to 21.0.2, 20.3.15, and 19.2.17. The vulnerability was published on December 1, 2025, and classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Technical Analysis
The root cause of this vulnerability lies in the incomplete security schema of the Angular Template Compiler. Attackers can exploit this weakness to inject harmful scripts into web applications. The attack vector is network-based, requiring a low attack complexity, indicating that an attacker can easily exploit the vulnerability without requiring extensive technical knowledge.
The attack requires low privileges, meaning that even users with limited access may inadvertently trigger the exploit. User interaction is also required, as the malicious script injection relies on the user's active participation to execute the attack.
This vulnerability has significant impacts on confidentiality, integrity, and availability. If successfully exploited, it can lead to unauthorized access to sensitive information, alteration of web content, and potentially disrupt the availability of the application.
Risk & Impact Analysis
Risk to organizations includes the potential for significant data breaches and the compromise of sensitive user information. The blast radius of this vulnerability could affect multiple applications built on Angular, leading to widespread exploitation if not addressed promptly.
Given the high severity and the potential for exploitation, organizations should prioritize patching immediately. Implementing the latest updates not only mitigates this specific vulnerability but also strengthens the overall security posture against similar threats.
Additionally, organizations should conduct thorough security assessments to identify and remediate any other potential vulnerabilities within their applications.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include Angular versions prior to 21.0.2, 20.3.15, and 19.2.17. Organizations should ensure they upgrade to these patched versions to mitigate the vulnerability.
Mitigation & Remediation
Organizations should prioritize updating to Angular versions 21.0.2, 20.3.15, and 19.2.17 to remediate the identified vulnerability. In cases where immediate patching is not feasible, consider implementing workarounds, such as applying additional security controls to sanitize user inputs more rigorously.
Further, organizations should undertake a thorough review of application configurations and ensure that appropriate network controls are in place to limit exposure to potential attacks.
Monitoring for any unusual activity or behavioral anomalies is essential to quickly identify and respond to potential exploitation attempts.
Continuous security testing can also assist in identifying any remaining vulnerabilities within the application stack.
Detection Guidance
To detect potential exploitation attempts of this vulnerability, organizations should monitor logs for indicators of successful script injections. Look for any behavioral anomalies, particularly those involving user interactions with web applications utilizing Angular.
Implementing network signatures to identify unusual traffic patterns can be beneficial. Additionally, keeping an eye on any unexpected changes to the application's structure or functionality is crucial in identifying potential security breaches.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of robust security measures in web application development. As organizations increasingly rely on frameworks like Angular for building dynamic applications, understanding the underlying security implications is paramount. The patterns observed in this vulnerability reflect ongoing challenges with XSS attacks across various frameworks.
Security teams should take this opportunity to reinforce their application security practices, including regular security assessments and user training to recognize potential threats. Adopting a proactive approach to security, such as implementing vulnerability management programs can help mitigate the risks associated with vulnerabilities like CVE-2025-66412.
Moreover, organizations should remain vigilant and keep abreast of emerging threats, ensuring that they are prepared to respond swiftly to any potential exploitation.
Regularly engaging in penetration testing can also be instrumental in identifying and addressing underlying vulnerabilities before they can be exploited.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)