CVE-2026-113021 in Chrome
Summary
by MITRE • 10/21/2026
Use after free in WebAppInstalls in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified as a use-after-free flaw within the WebAppInstalls component of Google Chrome prior to version 156.0.8078.47 represents a critical memory management error that can be leveraged by remote attackers to achieve arbitrary code execution. This specific class of bug occurs when a program continues to use a pointer after the memory it points to has been freed, often leading to undefined behavior that security researchers and threat actors exploit for malicious purposes. In this instance, the flaw resides in the logic governing how Chrome handles web application installations, specifically within the Chromium engine's handling of HTML pages requesting or managing app installation states. The severity is classified as Low by Chromium standards due to the complexity required to reliably trigger the condition and bypass modern sandboxing protections, yet it remains a significant risk because successful exploitation allows an attacker to execute code with the privileges of the compromised browser process.
From a technical perspective, use-after-free vulnerabilities are particularly dangerous in web browsers because they can often lead to heap corruption or arbitrary read/write primitives if not properly mitigated by memory safety features like ASAN (Address Sanitizer) or hardware-based protections such as Control Flow Integrity and DEP/NX bits. The attacker crafts an HTML page that triggers the installation process for a web application, causing Chrome to allocate specific resources in memory. When the operation completes or is aborted under certain conditions, these resources are deallocated but not immediately nullified or removed from active references within the browser's internal data structures. If the crafted page can induce the browser to access this stale pointer before it is reallocated for a different purpose, the attacker gains control over how that memory region is interpreted and used. This misinterpretation allows the injection of malicious payloads into the execution flow, effectively bypassing the isolation mechanisms designed to contain web content within a restricted sandbox environment.
The operational impact of this vulnerability centers on the potential compromise of user data and system integrity through remote code execution. Although Chrome employs a multi-process architecture where each tab or site runs in its own sandboxed process with limited permissions, successful exploitation can allow an attacker to escape these restrictions under specific circumstances or escalate privileges within the browser's context. This could lead to unauthorized access to sensitive information such as cookies, session tokens, and saved passwords stored by the browser. Furthermore, if the vulnerability allows for reliable memory corruption techniques like heap spraying combined with precise control over pointer dereferences, it may facilitate a sandbox escape, granting the attacker broader system-level access. The requirement for user interaction is typically minimal in these scenarios; often, simply visiting a maliciously crafted webpage or having one auto-load via an iframe can be sufficient to trigger the exploit vector without further engagement from the victim.
Mitigation strategies primarily involve immediate patching of the Google Chrome browser to version 156.0.8078.47 or later, which includes code changes that ensure proper memory management and prevent dangling pointers from being accessed after deallocation. Security teams should also enforce strict content security policies and utilize browser hardening techniques such as disabling unnecessary plugins or features related to web app installations if they are not required for business operations. Additionally, deploying endpoint detection and response solutions can help identify anomalous behavior indicative of exploitation attempts, such as unusual memory access patterns or unexpected process spawns following the loading of untrusted HTML content. Regularly updating all software components ensures that known vulnerabilities like this use-after-free flaw remain closed against active threat actors who frequently target browser engines for initial access vectors in cyberattacks.
This vulnerability aligns with CWE-416, which defines Use After Free as a weakness where a pointer is used after its memory has been freed, leading to unpredictable behavior and potential security breaches. In the context of the MITRE ATT&CK framework, this exploit technique falls under Tactic TA0002 Execution and specifically relates to techniques such as T1059 Command and Scripting Interpreter or potentially T1203 Exploitation for Client Execution if it leads to sandbox escape. Understanding these mappings helps security professionals categorize the risk accurately within their threat intelligence platforms and prioritize remediation efforts based on industry-standard classifications of vulnerability severity and exploitability.