CVE-2026-4680 in Chrome
Summary
by MITRE • 03/24/2026
Use after free in FedCM in Google Chrome prior to 146.0.7680.165 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 03/28/2026
The vulnerability identified as CVE-2026-4680 represents a critical use-after-free condition within the Federated Credential Management (FedCM) API implementation in Google Chrome versions prior to 146.0.7680.165. This flaw exists in the browser's credential management system that facilitates secure authentication with third-party identity providers through federated login mechanisms. The FedCM API allows websites to request authentication from identity providers without requiring users to navigate away from the current page, creating a seamless yet complex authentication flow that involves multiple browser components working in concert.
The technical root cause of this vulnerability stems from improper memory management within the FedCM implementation where freed memory blocks are still being accessed or referenced by subsequent operations. This use-after-free condition occurs when the browser's memory allocator releases a memory block that is subsequently accessed by the FedCM subsystem, creating a scenario where attacker-controlled data can overwrite the freed memory region. The flaw specifically manifests in the handling of credential objects during authentication flows, where the application fails to properly validate memory references before accessing them, allowing for potential memory corruption that can be exploited to gain unauthorized code execution privileges.
The operational impact of this vulnerability is severe as it enables remote code execution within the browser's sandboxed environment, representing a high-severity threat according to Chromium's security classification. Attackers can craft malicious HTML pages that trigger the vulnerable code path through carefully constructed credential requests and authentication flows that exploit the memory management flaw. The sandbox protection mechanisms that normally isolate browser processes from the underlying operating system are bypassed, allowing attackers to execute arbitrary code with the privileges of the browser process. This creates a significant risk for users who may unknowingly visit compromised websites or be targeted through phishing campaigns that leverage this vulnerability to deliver malicious payloads.
The exploitation of this vulnerability aligns with attack patterns commonly associated with memory corruption exploits and falls under the broader category of sandbox escape techniques. From a cybersecurity perspective, this flaw demonstrates the complexity of modern browser security architectures where even seemingly isolated components like credential management systems can contain vulnerabilities that undermine fundamental security assumptions. The vulnerability's classification as high severity reflects the ease with which remote attackers can leverage this flaw without requiring user interaction beyond visiting a malicious webpage, making it particularly dangerous in real-world scenarios where users may encounter such content through social engineering or compromised websites.
Organizations and users should immediately update to Chrome version 146.0.7680.165 or later to remediate this vulnerability, as no effective workarounds exist for this particular use-after-free condition. The fix implemented by Google addresses the memory management issue through proper validation of memory references and ensuring that freed objects are not accessed during the credential management flow. Security teams should monitor for any related indicators of compromise that may indicate exploitation attempts and consider implementing network-based protections such as web application firewalls that can detect and block malicious HTML content attempting to trigger this specific vulnerability. This vulnerability also underscores the importance of continuous security auditing of browser components and the need for robust memory safety practices in complex software systems where multiple security boundaries intersect.