CVE-2026-91710 in Chrome
Summary
by MITRE • 09/15/2026
Use after free in WebAppInstalls in Google Chrome prior to 153.0.8010.47 allowed a remote attacker to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified as a use-after-free condition within the WebAppInstalls component of Google Chrome prior to version 153.0.8010.47 represents a critical memory management error that compromises the browser's integrity and isolation mechanisms. This flaw arises when an object is deallocated from memory but remains accessible through existing pointers or references, allowing subsequent operations to interact with freed memory regions. In the context of Chrome’s architecture, such errors are particularly dangerous because they can bypass security boundaries designed to contain malicious activity within a restricted sandbox environment. The specific component involved, WebAppInstalls, handles the logic for installing web applications on user devices, making it a frequent target for exploitation due to its complex interaction with system resources and network data.
A remote attacker could exploit this vulnerability by crafting a deceptive HTML page that triggers the premature deallocation of an object while maintaining active references to it within the WebAppInstalls module. When the browser processes subsequent operations on these dangling pointers, it may read or write to arbitrary memory locations controlled by the attacker. This capability enables the execution of arbitrary code outside the confines of the sandbox, effectively breaking out of the restricted environment that protects the host system from untrusted web content. The severity is classified as High because successful exploitation grants an adversary significant control over the victim's machine without requiring any user interaction beyond visiting a malicious website or being redirected to one via phishing techniques.
From a technical perspective, this vulnerability aligns with CWE-416, which describes use-after-free errors resulting from improper handling of memory deallocation and reuse. The exploitation path typically involves manipulating object lifecycles during the installation process, where timing differences between pointer invalidation and usage create an exploitable window. This flaw also maps to MITRE ATT&CK technique T1203, specifically the sub-technique for exploitation via browser vulnerabilities, highlighting how attackers leverage software defects to achieve initial access and privilege escalation within a compromised system. The ability to execute code outside the sandbox is particularly concerning as it neutralizes one of Chrome’s primary defense layers against drive-by downloads and malicious script execution.
Mitigation strategies primarily involve updating Google Chrome to version 153.0.8010.47 or later, where this memory management issue has been resolved through rigorous code review and patching of the WebAppInstalls component. Organizations should enforce automated update policies to ensure all endpoints are running secure versions of the browser. Additionally, implementing strict content security policies can help mitigate some risks associated with executing untrusted scripts, although they do not directly prevent exploitation of this specific memory corruption flaw. Security teams should also monitor for indicators of compromise related to sandbox escape attempts and maintain awareness of emerging threats targeting web application installation mechanisms in popular browsers.