CVE-2026-118353 in Chrome
Summary
by MITRE • 10/28/2026
Use after free in Paint in Google Chrome prior to 156.0.8078.73 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 • 10/28/2026
The vulnerability identified as a use-after-free flaw within the Paint component of Google Chrome prior to version 156.0.8078.73 represents a critical memory management error that compromises the integrity and confidentiality of user data. This specific class of vulnerabilities occurs when an application continues to reference a pointer after the memory it points to has been freed, leading to undefined behavior that can be exploited by malicious actors. In this instance, the flaw resides in the rendering engine responsible for handling graphical operations within the browser's sandboxed environment. The Chromium security team classified this issue with high severity due to its potential impact on system stability and security posture, highlighting the critical nature of memory safety in modern web browsers where complex graphics processing is frequently performed via JavaScript APIs such as Canvas or WebGL.
The operational mechanism behind this exploitation involves a crafted HTML page that triggers specific rendering commands within Chrome's Paint subsystem. When the browser processes these maliciously constructed instructions, it allocates memory for graphical objects and subsequently frees that memory upon completion of certain operations. However, due to the logic error in the vulnerability, references to these freed memory blocks persist within internal data structures or event handlers. An attacker can manipulate the timing and sequence of these operations to reallocate the freed memory with controlled content before the stale pointer is dereferenced again. This allows the execution of arbitrary code within the context of the browser process, effectively bypassing standard security controls that rely on proper memory isolation.
From a technical perspective, this vulnerability aligns closely with CWE-416, which defines use-after-free errors as a category of software weaknesses resulting from improper resource management. The exploitation of such flaws often leads to arbitrary code execution, corresponding to the ATT&CK technique T1059, specifically through command and script interpreters or native API calls depending on the payload delivered via the crafted page. Because Chrome employs a multi-process architecture with sandboxing designed to limit the impact of successful exploits, achieving arbitrary code execution inside the sandbox is particularly dangerous. It indicates that the attacker has gained sufficient control over memory layout and state transitions to execute instructions within an environment intended to restrict access to sensitive system resources, potentially leading further into privilege escalation attacks if additional vulnerabilities are present in adjacent processes or plugins.
The impact of this vulnerability extends beyond immediate code execution. Successful exploitation could allow a remote attacker to steal cookies, session tokens, and other authentication credentials stored by the browser. It also enables the installation of malware on the victim's machine under the user's privileges, facilitating persistent access for future attacks. Furthermore, use-after-free vulnerabilities can sometimes be leveraged to achieve sandbox escapes if combined with additional techniques that exploit race conditions or heap spraying methods, thereby granting the attacker elevated permissions equivalent to those of the local user account. This underscores the importance of rigorous memory safety practices in browser development and the necessity of timely patching to mitigate risks associated with complex rendering engines.
Mitigation strategies primarily involve updating Google Chrome to version 156.0.8078.73 or later, where these memory management issues have been addressed through code fixes that ensure proper lifecycle management of graphical objects. Developers and system administrators should enforce automated update policies to minimize the window of exposure for end-users. Additionally, employing browser hardening techniques such as disabling unnecessary plugins, using content security policies, and leveraging sandboxing features can reduce the attack surface. Security teams should also monitor for indicators of compromise related to memory corruption exploits, including unusual CPU spikes or anomalous network activity originating from browser processes, which may signal active exploitation attempts targeting this specific vulnerability class.