CVE-2026-106393 in Chrome
Summary
by MITRE • 10/07/2026
Use after free in Storage in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as a use-after-free condition within Google Chrome's storage subsystem prior to version 155.0.8059.39 represents a critical memory management error that undermines the browser's core security architecture. This flaw specifically affects the handling of data stored in local or session storage mechanisms, where objects are deallocated from memory but references to those freed memory locations remain active within the application state. When an attacker crafts a malicious HTML page designed to trigger this specific sequence of events, they can manipulate the timing and content of subsequent allocations to overwrite the freed memory with controlled data structures. This manipulation allows for arbitrary code execution outside the renderer process sandbox, effectively bypassing Chrome's multi-process isolation model which is designed to contain exploits within isolated environments.
From a technical perspective, use-after-free vulnerabilities are among the most dangerous classes of software defects because they provide attackers with precise control over memory layout and content. In this instance, the flaw resides in how the storage component manages object lifecycles during dynamic updates or deletions. If an application accesses a pointer after the underlying memory has been returned to the system allocator but before it is reallocated for another purpose, the behavior becomes undefined. By carefully crafting the payload within the HTML page, an attacker can ensure that new data written into the freed block contains executable shellcode or pointers to existing code segments such as function addresses in shared libraries. This technique leverages common exploitation patterns like heap spraying or control flow hijacking to gain execution privileges at the level of the browser process rather than being confined to the restricted renderer context.
The operational impact of this vulnerability is severe, particularly given its classification by Chromium with a high security severity rating. A remote attacker who has already compromised the renderer process through another vector can escalate their privilege and execute arbitrary code on the victim's machine. This escalation breaks the fundamental assumption that untrusted web content cannot affect system-level resources or other browser processes. The ability to escape the sandbox allows for full compromise of the user environment, including access to sensitive files, installation of persistent malware, and interception of network traffic from other tabs or applications running under the same user account. Such an exploit chain is particularly dangerous in enterprise environments where browsers are often used with elevated trust levels or integrated into single sign-on systems that rely on browser integrity for authentication security.
Mitigation strategies primarily involve updating to Google Chrome version 155.0.8059.39 or later, which contains the necessary patches to correct the memory management logic within the storage subsystem. These updates typically include stricter checks on pointer validity before access and improved tracking of object lifetimes to prevent dangling references from being dereferenced. For organizations unable to patch immediately, implementing strict content security policies can help mitigate some risks by restricting script execution sources and preventing certain types of cross-origin data interactions that might be leveraged in exploitation attempts. Additionally, enabling sandboxing features such as site isolation ensures that even if a renderer is compromised, the blast radius remains limited due to process separation boundaries enforced at the operating system level.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-416, which describes use after free errors where software continues to use pointers that point to freed memory leading to unpredictable behavior and potential security breaches. In terms of attack tactics, this exploit maps directly to MITRE ATT&CK technique T1203, specifically the exploitation for client execution phase, where attackers leverage vulnerabilities in applications running on end-user systems to execute malicious code. The progression from renderer compromise to sandbox escape also reflects aspects of privilege escalation techniques found within lateral movement and defense evasion categories, highlighting the importance of maintaining up-to-date browser versions as a primary control against sophisticated web-based attacks that target memory safety flaws.