CVE-2025-53791 is a medium-severity vulnerability classified under CWE-284 (Improper Access Control) affecting Microsoft Edge (Chromium-based) version 1.0.0.0. This vulnerability allows an unauthorized attacker to bypass a security feature remotely over a network. The issue stems from improper enforcement of access control mechanisms within the browser, which could enable an attacker to perform actions or access resources that should be restricted. The CVSS 3.1 base score is 4.7, reflecting a network attack vector (AV:N) with high attack complexity (AC:H), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact is limited to low confidentiality and integrity impacts (C:L/I:L) with no impact on availability (A:N). The exploitability is currently unknown with no known exploits in the wild, and no patches have been linked yet. Given the Chromium-based architecture, this vulnerability could potentially be exploited via crafted web content or network-based attacks that trick users into interacting with malicious content, thereby bypassing intended security controls within the browser. This could lead to limited unauthorized data disclosure or modification within the browser context, potentially exposing sensitive information or enabling further attack chains.

For European organizations, this vulnerability poses a moderate risk primarily to confidentiality and integrity of data accessed or processed through Microsoft Edge. Since Edge is widely used in corporate environments across Europe, especially in enterprises standardized on Microsoft products, exploitation could lead to unauthorized access to sensitive information or manipulation of browser-based data. The requirement for user interaction reduces the likelihood of widespread automated exploitation but does not eliminate targeted phishing or social engineering attacks. The changed scope suggests that the vulnerability could affect components beyond the browser itself, potentially impacting integrated services or extensions. This could be particularly concerning for sectors handling sensitive personal data under GDPR, such as finance, healthcare, and government agencies, where even limited data leaks or integrity breaches can have regulatory and reputational consequences. However, the lack of known exploits and the high attack complexity somewhat mitigate immediate risks, though organizations should remain vigilant given the potential for future exploit development.

Organizations should prioritize updating Microsoft Edge to the latest version once a patch addressing CVE-2025-53791 is released by Microsoft. Until then, specific mitigations include: 1) Enforce strict user awareness and training programs to reduce the risk of social engineering and phishing attacks that require user interaction to exploit this vulnerability. 2) Implement network-level protections such as web filtering and intrusion detection systems to block or flag suspicious web content or network traffic targeting Edge browsers. 3) Restrict usage of Edge to trusted sites and consider deploying application control policies to limit execution of untrusted extensions or scripts. 4) Employ endpoint detection and response (EDR) solutions to monitor for anomalous browser behavior indicative of exploitation attempts. 5) Use browser security features such as Enhanced Protected Mode and sandboxing to contain potential impacts. 6) Regularly audit and review browser configurations and permissions to ensure minimal exposure. These targeted steps go beyond generic advice by focusing on reducing the attack surface and user interaction risks specific to this vulnerability.