The vulnerability has been discovered within the Loader component of Chrome and Chromium browsers. It is linked to how these browsers interpret the Link HTTP header for sub-resource requests such as images or scripts. While most mainstream browsers follow strict guidelines for handling such requests, Chrome’s unique behavior stands out. It continues to respect the referrer-policy directive even when loading sub-resources, which can unintentionally expose sensitive information.
This default behavior can be manipulated by attackers. A malicious site could inject a loose policy like “unsafe-url,” which then forces the browser to reveal complete URLs—including potentially sensitive credentials or session data—to third-party servers. This results in a severe breach of user privacy and circumvents traditional browser security measures.
Cybersecurity firm Wazuh has stated that their Vulnerability Detection module can identify and address this specific flaw.
The module leverages information from their Cyber Threat Intelligence (CTI) service to monitor browser versions and trigger alerts when vulnerable builds are detected. In controlled testing using Wazuh OVA 4.12.0, researchers were able to scan systems running Windows 11 and Debian 11 to determine if they were running affected versions of Chrome or Chromium.
According to Wazuh’s platform, users can search for the vulnerability by querying CVE-2025-4664. If vulnerable software is found, the module changes the system status from “Active” to “Solved” after the necessary fixes are applied, helping administrators track progress in real time.
In response to the discovery, Google has issued an emergency patch for Chrome users on Windows and Gentoo Linux. It is strongly recommended that users on these operating systems update their browsers immediately to avoid exposure. However, users on Debian 11 who rely on Chromium remain at risk, as no updated version has been released for that platform. All Chromium builds up to version 120.0.6099.224 are still considered vulnerable. Until a patch is available, security professionals advise uninstalling Chromium on affected Debian systems as a precautionary measure.
While these immediate actions are important, experts caution that relying solely on browser updates is not a comprehensive defense. The broader cybersecurity strategy must include the use of endpoint protection platforms, anti-malware systems, and modern antivirus tools. These security layers can help detect and neutralize threats that slip past browser-based defenses and provide a stronger safety net for users and enterprises alike.
As browser-based zero-day threats continue to emerge, users must remain vigilant. Rapid patching combined with proactive cybersecurity tools offers the best chance of mitigating risks and maintaining a secure browsing environment.
