CVE-2026-76028 in Chrome
Summary
by MITRE • 10/30/2026
Use after free in FileSystem in Google Chrome prior to 156.0.8078.79 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified as a use-after-free flaw within the FileSystem component of Google Chrome prior to version 156.0.8078.79 represents a critical memory management error that can be leveraged by remote attackers to achieve arbitrary code execution. This type of defect 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 exploit developers can manipulate to gain control over process execution flow. In the context of web browsers like Chrome, such vulnerabilities are particularly dangerous because they reside within components designed to handle complex data structures from untrusted sources on the internet. The FileSystem API allows websites to interact with local file systems in a controlled manner, but if the internal state management fails to properly invalidate references after memory deallocation, an attacker can craft specific HTML pages that trigger this race condition or logic error during file operations.
From a technical perspective, the core issue lies in the lifecycle management of objects within the FileSystem implementation. When resources are released, the associated pointers must be nullified or otherwise protected from further access to prevent dangling references. However, due to the complexity of asynchronous web APIs and multi-threaded environments typical in modern browsers, it is possible for a reference to remain valid even after the underlying memory has been returned to the heap allocator. An attacker can exploit this window by allocating new data at the same memory address using crafted inputs, effectively controlling what that freed pointer now references. This allows the injection of malicious payloads into the browser process context, bypassing standard security boundaries through careful manipulation of object headers and function pointers within the vtable or similar structures used for polymorphic dispatch in C++ based codebases like Chromium.
The operational impact of this vulnerability is severe due to its potential for remote exploitation via a simple crafted HTML page. Users visiting maliciously designed websites could inadvertently trigger the flaw without any additional interaction beyond loading the page, depending on how the FileSystem API is invoked by the site's JavaScript. Although Chrome employs multiple layers of defense including sandboxing, heap hardening techniques like ASLR and DEP, and control flow integrity mechanisms, a successful use-after-free exploit can often bypass these protections through sophisticated chaining attacks or specific memory layout assumptions that hold true in many deployment environments. The Chromium security team has classified this issue with high severity, reflecting the likelihood of exploitation and the significant impact on user confidentiality and system integrity if arbitrary code execution is achieved within the browser process sandbox.
To mitigate risks associated with such vulnerabilities, organizations should ensure that all instances of Google Chrome are updated to version 156.0.8078.79 or later where this flaw has been addressed by correcting the memory management logic in the FileSystem component. Beyond immediate patching, defense-in-depth strategies remain essential. Security teams should enforce strict content security policies and restrict permissions for web applications that require access to sensitive APIs like File System Access. Additionally, enabling automatic updates ensures that users receive critical patches promptly as they are released. Monitoring browser telemetry for anomalous behavior can also help detect potential exploitation attempts in real-time.
This vulnerability aligns with CWE-416, which describes Use After Free conditions where a pointer is used after its memory has been freed, leading to unpredictable program behavior and potential security breaches. In terms of offensive cybersecurity frameworks, this exploit technique maps closely to ATT&CK Tactic TA0002 Execution, specifically techniques involving client-side code execution such as browser exploitation via scripting or HTML manipulation (T1059). Understanding these mappings helps in categorizing the threat landscape and prioritizing remediation efforts based on established industry standards for vulnerability management. By addressing both the specific software defect and implementing broader security controls, organizations can significantly reduce their exposure to remote code execution attacks targeting web browsers.