CVE-2026-76026 in Chrome
Summary
by MITRE • 10/30/2026
Memory corruption in Autofill in Google Chrome prior to 156.0.8078.79 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified as a memory corruption issue within the Autofill component of Google Chrome prior to version 156.0.8078.79 represents a critical failure in boundary checking and data handling mechanisms inherent to web browser interfaces. This flaw allows for arbitrary code execution inside the sandbox, which is a significant security escalation because browsers rely on sandboxes to isolate untrusted content from the host operating system. The Autofill feature, designed to automatically populate form fields with user information such as addresses or credit card details, involves complex parsing and rendering of HTML structures. When processing crafted input that triggers this vulnerability, the browser fails to properly validate memory allocations or pointer operations, leading to conditions where an attacker can overwrite adjacent memory regions. This typically manifests as a heap-based buffer overflow or use-after-free condition, depending on the specific internal implementation details of how Autofill manages temporary data structures during form interaction and submission processes.
From a technical perspective, this vulnerability falls under the category of CWE-120 Buffer Copy without Checking Size of Input and CWE-416 Use After Free, which are common precursors to arbitrary code execution in modern software environments. The attacker crafts an HTML page that exploits these memory management errors by supplying malformed or excessively large inputs that exceed expected buffer limits or reference freed memory locations. When the browser processes this malicious content, it attempts to write data beyond allocated boundaries or accesses memory that has already been released back to the system allocator. This corruption allows the injection of shellcode into the process memory space, effectively bypassing standard protection mechanisms such as Data Execution Prevention and Address Space Layout Randomization if combined with additional exploitation techniques like ROP chains. The severity is rated High by Chromium because it enables remote code execution without user interaction beyond visiting a malicious webpage, leveraging social engineering or drive-by download tactics to compromise the victim's system.
The operational impact of this vulnerability extends far beyond simple data theft. Since the attack occurs within the browser sandbox, successful exploitation grants the attacker control over the browser process with limited privileges initially. However, through further privilege escalation techniques available in many operating systems, an attacker can break out of the sandbox to gain full access to the underlying host system. This leads to complete compromise of the victim's machine, allowing for installation of persistent backdoors, exfiltration of sensitive data including credentials stored by Autofill, and use of the compromised device as part of a botnet. The ability to execute arbitrary code remotely makes this vulnerability particularly dangerous in enterprise environments where employees may inadvertently visit malicious sites containing exploit kits designed specifically for browser vulnerabilities.
Mitigation strategies primarily involve immediate patching to version 156.0.8078.79 or later, which includes fixes for the underlying memory management flaws in the Autofill module. Organizations should ensure that automatic updates are enabled for all Chrome installations across their network perimeter and endpoint devices. Additionally, implementing application whitelisting policies can restrict the execution of untrusted scripts within browser contexts, reducing the attack surface even if a zero-day vulnerability were present. Security teams should also monitor for indicators of compromise related to unusual memory allocation patterns or unexpected outbound connections from browser processes, which may indicate active exploitation attempts using this specific flaw in conjunction with ATT&CK techniques such as T1059 Command and Scripting Interpreter and T1203 Exploitation for Client Execution. Regular vulnerability scanning and penetration testing focused on web application security can help identify similar implementation weaknesses before they are exploited by threat actors.