CVE-2026-76021 in Chrome
Summary
by MITRE • 08/21/2026
Use after free in DOM in Google Chrome prior to 151.0.7922.173 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/21/2026
The vulnerability described constitutes a critical use-after-free condition within the Document Object Model implementation of Google Chrome prior to version 151.0.7922.173, representing a significant breach in memory safety protocols that can be leveraged by remote attackers to achieve arbitrary code execution within the browser's sandboxed environment. This type of flaw typically arises when an object is deallocated or freed from memory while there are still active references pointing to it, allowing subsequent access operations to interact with invalid or recycled memory addresses rather than properly secured data structures. In the context of web browsers, such vulnerabilities often stem from complex interactions between JavaScript engines and rendering components where lifecycle management fails to correctly track reference counts or clear dangling pointers after an element is removed from the DOM tree but remains accessible through event handlers or asynchronous callbacks.
From a technical perspective, this flaw aligns with CWE-416, which defines use-after-free errors as accessing memory that has already been freed, leading to unpredictable behavior such as crashes, data corruption, or code execution. The severity is classified as high because the attacker can craft an HTML page containing malicious JavaScript and embedded objects designed to trigger the specific sequence of events required to free a DOM node while retaining a reference to it through another part of the script. When the browser attempts to access this freed memory, it may interpret the contents based on how that memory has been reallocated for other purposes, potentially allowing the attacker to control pointer values or overwrite critical function pointers within the V8 engine or rendering process structures. This mechanism bypasses standard sandbox protections by exploiting the trust relationship between different renderer processes and the browser's core components, effectively elevating privileges from a restricted web context to one capable of executing native code on the host system.
The operational impact of this vulnerability is severe, as it enables remote code execution without any user interaction beyond visiting a maliciously crafted webpage or clicking a link that loads such content. Attackers can utilize social engineering tactics combined with exploit kits to deliver these payloads via phishing emails, compromised websites, or drive-by downloads. Once executed within the sandbox, the malware may attempt further privilege escalation techniques to break out of the browser container and gain control over the underlying operating system. This could lead to full compromise of the victim's machine, including theft of sensitive data such as credentials, financial information, and personal documents stored locally on the device. The ability to execute arbitrary code also facilitates persistent backdoors, keylogging capabilities, and lateral movement within corporate networks if the compromised browser is used for professional activities connected to internal resources.
Mitigation strategies primarily involve immediate patching by upgrading Google Chrome to version 151.0.7922.173 or later, which includes fixes that enforce stricter memory management practices and validate object lifecycles before allowing access operations. Organizations should ensure automated update mechanisms are enabled for all endpoints running the browser to minimize exposure windows. Additionally, security teams can implement application control policies using tools like Windows Defender Application Control or macOS Gatekeeper to restrict execution of untrusted scripts within browser contexts where possible. Network-level defenses such as web filtering proxies and intrusion prevention systems configured with signatures targeting known exploit kits associated with this vulnerability class provide an additional layer of defense against initial access attempts. From a development standpoint, adopting memory-safe languages for critical components like the DOM parser or utilizing static analysis tools that detect dangling pointer scenarios during code review can prevent similar issues in future releases.
This incident underscores the importance of continuous monitoring and rapid response capabilities within security operations centers dealing with browser-based threats. The ATT&CK framework categorizes this type of exploitation under T1203, which covers Exploitation for Client Execution, highlighting how attackers leverage software vulnerabilities to run malicious code on target systems. Understanding these attack patterns allows defenders to better configure endpoint detection and response solutions to identify anomalous behavior indicative of such exploits, such as unusual memory allocation patterns or unexpected process spawns originating from browser processes. Regular vulnerability assessments and penetration testing focused on web application security can further help organizations identify potential entry points before they are exploited in the wild by threat actors seeking high-value targets.