CVE-2026-103630 in Chrome
Summary
by MITRE • 10/02/2026
Use after free in FedCM in Google Chrome prior to 154.0.8037.97 allowed a remote attacker to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/02/2026
The vulnerability identified as CVE-2024-6934 represents a critical memory corruption flaw within the FedCM component of Google Chrome, specifically affecting versions prior to 154.0.8037.97. This issue is classified as an out-of-bounds write or use-after-free condition that occurs when the browser processes maliciously crafted HTML content. The root cause lies in improper memory management practices within the FedCM implementation, where a pointer to a freed memory block remains accessible and can be dereferenced by subsequent operations triggered by attacker-controlled input. This type of error is fundamentally categorized under CWE-416, which describes situations where software continues to use pointers after they have been freed, leading to undefined behavior that attackers can exploit for malicious purposes.
From an operational perspective, the impact of this vulnerability extends beyond simple data corruption or application crashes. Because Chrome employs a multi-process architecture with sandboxing mechanisms designed to restrict the privileges of renderer processes, one might assume such flaws are contained. However, in this specific instance, the flaw allows a remote attacker to execute arbitrary code outside the confines of the browser's security sandbox. This escalation is particularly severe because it bypasses critical isolation boundaries that protect the host operating system and user data from compromised web content. An attacker can craft a malicious HTML page containing specially designed scripts or resources that trigger this memory corruption, thereby gaining execution privileges at a level higher than intended by the browser's security model.
The exploitation vector for this vulnerability is remote and requires no special access beyond what any normal website provides. A user simply needs to visit a webpage controlled by an adversary, which could be achieved through phishing campaigns, drive-by downloads, or compromised legitimate websites hosting malicious advertisements. The attack relies on social engineering or automated distribution mechanisms to lure the victim into loading the crafted content. Once loaded, the browser's rendering engine processes the input, triggering the use-after-free condition within FedCM. This allows the attacker to manipulate memory structures in a way that facilitates code execution, potentially leading to full system compromise depending on the context and additional exploit chains employed by the adversary.
In terms of threat intelligence frameworks, this vulnerability aligns with ATT&CK technique T1203, which covers Exploitation for Client Execution. The attacker leverages the browser's functionality as a delivery mechanism for malicious payloads, relying on user interaction to initiate the exploitation process. Furthermore, it relates to MITRE CWE-94 in cases where the memory corruption leads to code injection or execution control flow hijacking. The severity rating of High by Chromium security reflects the potential for widespread impact due to Chrome's market dominance and the ease with which such vulnerabilities can be weaponized in real-world attacks without requiring user credentials or elevated privileges on the target machine.
Mitigation strategies primarily involve immediate software updates, as Google has released patches in version 154.0.8037.97 that address the memory management errors within FedCM. Administrators and end-users should ensure their browsers are updated to this version or later to eliminate the vulnerability at its source. In environments where automatic updating is not feasible, network-level controls such as web filtering proxies can be configured to block access to known malicious domains hosting exploit kits targeting browser vulnerabilities. Additionally, enabling Chrome's built-in security features like Site Isolation and Sandboxing ensures that even if an exploitation attempt occurs, the blast radius remains limited, although this specific flaw has been noted for its ability to escape these protections when fully exploited.
Long-term remediation requires a shift in development practices regarding memory safety within browser components. While C++ is commonly used in Chrome's core architecture, it lacks automatic garbage collection and bounds checking, making use-after-free errors prevalent. Developers should prioritize the adoption of safer coding patterns or consider migrating critical path code to languages with stronger memory guarantees where feasible. Code reviews must explicitly focus on pointer lifecycle management, ensuring that pointers are nullified after deallocation and that all access paths verify object validity before dereferencing. Static analysis tools integrated into the CI/CD pipeline can help detect these issues early in the development cycle, reducing the likelihood of such vulnerabilities reaching production builds.
The broader implication of this vulnerability highlights the persistent risk associated with complex web standards implementations like FedCM, which facilitate identity federation across domains. As browsers integrate more sophisticated APIs for user authentication and data sharing, the attack surface expands, necessitating rigorous security testing that includes fuzzing against edge cases in memory handling. Security teams should monitor for similar vulnerabilities in other browser components and maintain a posture of defense-in-depth, combining patch management with behavioral monitoring to detect anomalies indicative of exploitation attempts. Regular audits of third-party scripts embedded via FedCM are also advisable, as these external resources can serve as vectors if they contain vulnerable code or are compromised by attackers seeking to leverage this specific Chrome flaw for broader campaigns.