CVE-2026-118320 in Chrome
Summary
by MITRE • 10/28/2026
Memory corruption in V8 in Google Chrome prior to 156.0.8078.73 allowed a remote attacker to potentially execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability identified within the V8 JavaScript engine, which powers Google Chrome prior to version 156.0.8078.73, represents a critical memory corruption flaw that undermines the browser's core security model. This issue stems from improper handling of data structures or object states during the execution of JavaScript code embedded in web pages. When an attacker crafts a malicious HTML page containing specific scripts designed to trigger this condition, they can manipulate how V8 manages memory allocations and references. The root cause typically involves race conditions, use-after-free scenarios, or buffer overflows within the engine's internal mechanisms for managing objects and their lifecycles. Because V8 operates at a low level close to the hardware, errors in its memory management logic allow an attacker to corrupt adjacent memory regions, leading to unpredictable behavior that can be exploited to gain control over program execution flow.
From a technical perspective, this flaw allows a remote attacker to achieve arbitrary code execution within the browser's sandboxed environment. Modern browsers rely heavily on sandboxes to isolate web content from the underlying operating system and user data. However, memory corruption vulnerabilities like this one provide a pathway for an attacker to escape these restrictions by overwriting function pointers or return addresses in memory. By carefully crafting the payload, the attacker can redirect execution to shellcode injected into the process memory. This effectively breaks out of the V8 sandbox, granting the malicious code elevated privileges within the browser context. The severity is classified as high because it enables a remote attack vector without requiring user interaction beyond visiting a compromised or specially crafted website, making it suitable for drive-by download attacks and widespread exploitation campaigns targeting unpatched systems.
The operational impact of this vulnerability extends beyond simple script execution to potential full system compromise if the browser sandbox fails to contain the breach completely. An attacker leveraging this flaw could install malware, steal sensitive information such as cookies and session tokens, or use the compromised machine as a pivot point for further network attacks. The existence of such flaws in widely used browsers like Chrome highlights the persistent challenge of maintaining robust security boundaries in complex software ecosystems. Even with advanced mitigation techniques like Control Flow Integrity (CFI) and hardware-enforced stack protection, sophisticated memory corruption bugs can sometimes bypass these defenses if they exploit subtle timing issues or edge cases in object lifecycle management. This underscores the importance of regular updates to browser engines where such low-level fixes are frequently deployed to close gaps that could be weaponized by state-sponsored actors or cybercriminal syndicates.
To mitigate the risks associated with this vulnerability, organizations and individual users must ensure that Google Chrome is updated to version 156.0.8078.73 or later immediately upon availability. This patch includes corrections for the memory handling logic in V8 that prevents the exploitation of these specific corruption flaws. In addition to updating software, implementing defense-in-depth strategies such as strict Content Security Policy (CSP) headers can help limit the impact if a similar vulnerability is exploited by restricting script execution sources and preventing inline scripts where possible. Furthermore, enabling automatic updates for browsers ensures that critical security patches are applied promptly without relying on manual intervention from end-users who may not be aware of emerging threats. Monitoring browser update channels and participating in bug bounty programs can also contribute to faster identification and resolution of such high-severity issues before they become widely exploited in the wild.
This vulnerability aligns with Common Weakness Enumeration (CWE) categories related to memory safety, specifically CWE-120 Buffer Copy without Checking Size of Input or CWE-416 Use After Free, depending on the exact nature of the corruption within V8's implementation. In terms of attack tactics, it maps to MITRE ATT&CK techniques involving initial access through browser exploitation and execution via script interpretation. The ability to execute arbitrary code inside a sandboxed environment is particularly dangerous because it challenges the fundamental assumption that web content cannot affect host system integrity. Security teams should prioritize patching this vulnerability across all endpoints connected to corporate networks, as browsers are often the primary entry point for phishing campaigns and malicious advertising networks. Continuous monitoring of browser telemetry and anomaly detection systems can also help identify attempts to exploit such memory corruption flaws in real-time, providing an additional layer of defense beyond static patch management.