CVE-2025-4664 is a vulnerability identified in Google Chrome versions prior to 136.0.7103.113, specifically related to insufficient policy enforcement in the Loader component. The Loader is responsible for managing resource loading and enforcing security policies such as the Same-Origin Policy (SOP), which is critical for preventing unauthorized data access across different web origins. Due to this insufficient enforcement, a remote attacker can craft a malicious HTML page that exploits this weakness to leak cross-origin data. This means that sensitive information from other websites or web applications loaded in the browser could be accessed by the attacker without proper authorization. The vulnerability does not require any privileges or prior authentication but does require user interaction, such as visiting the malicious page. The CVSS score of 4.3 (medium severity) reflects that the impact is limited to confidentiality (partial data leak), with no impact on integrity or availability. The attack vector is network-based, with low attack complexity and no privileges required, but user interaction is necessary. There are no known exploits in the wild at the time of publication, and no official patch links were provided, indicating that users should update to version 136.0.7103.113 or later once available. This vulnerability highlights the importance of strict policy enforcement in browser components to prevent cross-origin data leakage, which can undermine user privacy and security.

For European organizations, this vulnerability poses a risk primarily to the confidentiality of sensitive data accessed via web browsers. Since Google Chrome is widely used across enterprises and public sectors in Europe, the potential for cross-origin data leakage could expose confidential business information, personal data protected under GDPR, and other sensitive content to unauthorized parties. This could lead to data breaches, regulatory non-compliance, reputational damage, and potential financial penalties. The requirement for user interaction means that phishing or social engineering campaigns could be used to lure users into visiting malicious pages, increasing the risk of exploitation. Sectors such as finance, healthcare, government, and critical infrastructure, which handle highly sensitive data, could be particularly impacted if attackers leverage this vulnerability to exfiltrate information. However, the medium severity and lack of known exploits suggest that while the threat is real, it is not currently widespread or easily exploitable at scale.

European organizations should prioritize updating Google Chrome browsers to version 136.0.7103.113 or later as soon as the patch is officially released. In the interim, organizations can implement browser security policies that restrict or monitor the loading of untrusted or suspicious web content, such as using Content Security Policy (CSP) headers and disabling or limiting JavaScript execution from untrusted sources. User awareness training should emphasize the risks of visiting unknown or suspicious websites to reduce the likelihood of successful social engineering attacks. Network-level protections, including web filtering and intrusion detection systems, can help block access to known malicious domains or detect anomalous browser behavior. Additionally, organizations should audit and monitor browser extensions and plugins, as these can sometimes be vectors for exploitation or data leakage. Regular vulnerability scanning and penetration testing focused on browser security can help identify and remediate related weaknesses proactively.