CVE-2026-106409 in Chrome
Summary
by MITRE • 10/07/2026
Incorrect reference resolution in WebAppInstalls in Google Chrome on on Mac prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to execute arbitrary code outside the sandbox via crafted network traffic. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an incorrect reference resolution within the WebAppInstalls component of Google Chrome on macOS represents a significant breach in browser isolation mechanisms, specifically affecting versions prior to 155.0.8059.39. This flaw stems from improper handling of object references during the installation or management of web applications, which are essentially progressive web apps that have been installed for offline use and desktop integration. In modern browsers like Chrome, security is heavily reliant on process isolation, where different tabs and components run in separate sandboxed processes to limit the impact of a compromise. The renderer process, responsible for executing JavaScript and rendering page content, operates under strict restrictions designed to prevent it from accessing sensitive system resources or executing arbitrary code outside its designated environment. However, this vulnerability allows an attacker who has already achieved execution within the renderer process to bypass these sandbox boundaries through crafted network traffic that triggers the flawed reference resolution logic.
From a technical perspective, the core issue lies in how Chrome manages memory references and object lifecycles during the WebAppInstalls operations. When specific network requests are processed, particularly those related to installing or updating web apps, the browser may incorrectly resolve pointers or fail to properly validate the integrity of referenced objects before use. This type of error is characteristic of a Use-After-Free vulnerability or an improper memory management flaw where stale references point to memory locations that have been reallocated for different purposes. By crafting specific network payloads, an attacker can manipulate these internal states, causing the browser to execute code in a context with higher privileges than intended. The severity rating of Medium by Chromium reflects the complexity required to exploit this condition and the fact that it requires prior compromise of the renderer process, yet its impact is critical because it leads to full sandbox escape, granting the attacker control over the host system rather than just the browser tab.
The operational impact of this vulnerability is severe for any user running an affected version of Chrome on macOS. Once a remote attacker successfully exploits this flaw by tricking a victim into visiting a malicious website or loading compromised content, they can execute arbitrary code with the privileges of the current user. This effectively neutralizes one of the most important security features of modern web browsers: the sandbox. With full system access, an attacker could install persistent malware, exfiltrate sensitive data such as passwords and financial information stored in browser profiles, or use the compromised machine as a pivot point for further attacks within a network. The ability to execute code outside the sandbox means that traditional endpoint detection systems relying on behavioral analysis of renderer processes may fail to detect the malicious activity immediately, allowing the attacker to establish persistence and move laterally with minimal resistance.
This vulnerability aligns closely with Common Weakness Enumeration (CWE) categories such as CWE-416: Use After Free, which describes situations where a program continues to use a pointer after it has been freed, leading to undefined behavior that can be exploited for code execution. Additionally, in the context of the MITRE ATT&CK framework, this exploit technique falls under T1059: Command and Scripting Interpreter, specifically within the scope of sandbox escape techniques like T1620: Reflective Code Loading or general privilege escalation methods used to break out of containerized environments. The attack vector is classified as Network (T1190), indicating that it can be triggered remotely without user interaction beyond visiting a malicious site, although some versions might require specific interactions depending on how the web app installation prompts are handled.
Mitigation for this vulnerability primarily involves updating Google Chrome to version 155.0.8059.39 or later, where these reference resolution issues have been corrected by developers through improved memory management and stricter validation of object states during WebAppInstalls operations. For organizations unable to patch immediately due to compatibility concerns, implementing strict content security policies (CSP) can help mitigate the risk by restricting the sources from which scripts are loaded, thereby reducing the likelihood of executing malicious payloads in the renderer process. Additionally, deploying browser isolation solutions or web gateways that filter network traffic before it reaches the client machine can provide an additional layer of defense against crafted requests designed to trigger this flaw. Regular security awareness training for users is also recommended to minimize the risk of visiting compromised websites that might attempt to exploit such vulnerabilities through social engineering tactics combined with technical exploitation.