CVE-2026-95356 in Chrome
Summary
by MITRE • 09/29/2026
Use after free in WindowDialog in Google Chrome prior to 154.0.8037.57 allowed a remote attacker leveraging social engineering to potentially 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 flaw within the WindowDialog component of Google Chrome prior to version 154.0.8037.57 represents a critical memory corruption issue that undermines the browser's sandboxing mechanisms. This specific class of vulnerabilities arises when software continues to reference a pointer after its associated memory has been freed and potentially reallocated for other purposes. In the context of Chrome’s architecture, where different tabs and processes are isolated via sandboxes to limit the impact of potential exploits, such an error is particularly dangerous because it can allow an attacker to manipulate how the browser interprets data in memory, effectively bypassing these isolation boundaries.
The technical root cause lies in the lifecycle management of objects within the WindowDialog interface. When a dialog window is closed or destroyed, the underlying C++ object may be deallocated from heap memory. However, if subsequent code attempts to access this object through a dangling pointer without verifying its validity first, it results in undefined behavior. An attacker can exploit this race condition by crafting an HTML page that triggers the creation and immediate destruction of a dialog window while simultaneously maintaining references to it. By carefully controlling the timing and content of memory allocations following the free operation, the attacker can overwrite adjacent heap metadata or data structures with malicious payloads. This manipulation allows for arbitrary read and write primitives within the browser process space.
The operational impact of this vulnerability is severe due to its potential for remote code execution outside the sandbox environment. Although exploitation typically requires social engineering tactics such as tricking a user into visiting a specially crafted website, the consequence of successful exploitation is full system compromise. Once an attacker achieves arbitrary code execution within the browser process with elevated privileges or by escaping the sandbox, they can install malware, steal sensitive credentials, monitor keystrokes, and access files that should be protected from web-based attacks. The critical severity rating assigned by Chromium reflects the high likelihood of exploitability given the prevalence of such memory corruption bugs in complex software like browsers and the significant security implications of breaking out of the browser sandbox.
This vulnerability aligns with Common Weakness Enumeration CWE-416, which describes use after free errors where a pointer is used after it has been freed or deallocated. From an offensive security perspective, this attack vector maps to MITRE ATT&CK techniques related to initial access via spearphishing links and subsequent privilege escalation through sandbox escape mechanisms like T1055 or specific browser exploitation paths such as T1203. The lack of proper pointer nullification or bounds checking in the WindowDialog implementation highlights a gap in defensive coding practices that modern browsers strive to mitigate through rigorous memory safety standards.
Mitigation strategies primarily involve updating Google Chrome to version 154.0.8037.57 or later, where these memory management issues have been addressed by developers. For organizations managing large fleets of endpoints, deploying automated patching solutions ensures that users are protected against such exploits before they can be leveraged in the wild. Additionally, enabling Chrome’s built-in sandbox protections and keeping operating system-level security features like Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) active provides additional layers of defense that make exploitation more difficult even if a vulnerability is present. Security awareness training for users remains crucial to prevent social engineering attacks that serve as the initial delivery mechanism for this type of exploit.