CVE-2026-95339 in Chrome
Summary
by MITRE • 09/29/2026
Use after free in ServiceWorker in Google Chrome prior to 154.0.8037.57 allowed a remote attacker to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Critical)
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified as a use-after-free condition within the ServiceWorker component of Google Chrome prior to version 154.0.8037.57 represents a critical memory safety flaw that undermines the browser's sandboxing mechanisms. This specific class of error occurs when a program continues to use a pointer after the memory it points to has been freed, leading to undefined behavior that can be exploited by malicious actors. In the context of web browsers, ServiceWorkers act as script backgrounds that enable features like offline experiences and push notifications, operating in an isolated environment designed to limit their access to system resources. When this isolation is compromised through a use-after-free vulnerability, it allows for potential escape from these restrictive boundaries, thereby elevating the threat level significantly beyond typical cross-site scripting or content injection attacks.
From a technical perspective, the root cause lies in improper management of memory lifecycles within the ServiceWorker runtime environment. An attacker could craft a malicious HTML page that triggers specific JavaScript operations to force the premature deallocation of an object while references to that same object remain active elsewhere in the application's execution flow. When the browser subsequently attempts to access or manipulate this dangling pointer, it may interpret arbitrary memory contents as valid code instructions or data structures. This misinterpretation can lead to arbitrary code execution within the context of the browser process, effectively bypassing the sandbox protections intended to contain web content and prevent unauthorized system modifications.
The operational impact of such a vulnerability is severe, particularly given its classification with critical severity by Chromium security teams. A successful exploit allows remote attackers to execute arbitrary commands on the victim's machine without any user interaction beyond visiting the crafted webpage. This capability facilitates data exfiltration, installation of persistent malware, or further lateral movement within a network if the compromised browser session is used as an entry point for subsequent attacks. The ability to escape the sandbox means that the attacker gains privileges equivalent to those of the current user running the browser, which can include access to sensitive files, cookies containing authentication tokens, and other personal information stored locally by the application.
Industry standards categorize this type of flaw under CWE-416, Use After Free, which highlights the failure to properly manage memory deallocation relative to object usage. Furthermore, in terms of tactical execution within the MITRE ATT&CK framework, this vulnerability aligns with techniques related to Initial Access and Privilege Escalation, specifically leveraging browser vulnerabilities for code execution. The exploitation path typically involves social engineering or drive-by download tactics where a user is directed to a malicious site that triggers the memory corruption sequence automatically upon page load.
Mitigation strategies primarily involve immediate patching of the affected software version. Users should upgrade Google Chrome to version 154.0.8037.57 or later, which includes fixes for this specific memory management error within the ServiceWorker component. Additionally, organizations can implement defense-in-depth measures such as enabling sandboxed iframes where possible and utilizing browser hardening configurations that restrict script execution privileges. Regular security awareness training remains essential to reduce the likelihood of users interacting with malicious web content, although technical controls like automatic updates are the most effective primary countermeasure against this specific class of vulnerability.