CVE-2026-85051 in Chrome
Summary
by MITRE • 09/03/2026
Type confusion in Compositing in Google Chrome prior to 152.0.7977.82 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 • 09/03/2026
The vulnerability described constitutes a critical type confusion flaw within the compositing subsystem of Google Chrome, specifically affecting versions prior to 152.0.7977.82. This defect arises from an inconsistency in how the browser handles object types during the rendering and composition process, allowing for improper interpretation of memory structures by the underlying engine. In modern web browsers, the compositing layer is responsible for managing visual layers and optimizing rendering performance by separating content into distinct composited elements. When a crafted HTML page triggers this specific code path, it manipulates internal data structures in a way that causes the browser to treat an object of one type as another unrelated type. This misalignment leads to memory corruption because operations expected on the original type are performed on the incorrectly interpreted structure, resulting in out-of-bounds writes or reads within the sandboxed renderer process.
From a technical perspective, this issue is classified under CWE-843, which denotes access of incorrect pointer type, and aligns with ATT&CK technique T1059, Command and Scripting Interpreter, as it facilitates arbitrary code execution. The severity is rated high because successful exploitation allows an attacker to bypass the browser's sandbox isolation mechanisms. Although Chrome employs a multi-process architecture where renderer processes are confined within sandboxes to limit the impact of vulnerabilities, type confusion bugs in core components like compositing can often lead to heap corruption that compromises these boundaries. By carefully crafting memory layouts and exploiting the timing or state inconsistencies inherent in the bug, an attacker can achieve arbitrary read-write primitives, which serve as the foundation for executing malicious code with the privileges of the compromised process.
The operational impact of this vulnerability is severe, enabling remote attackers to execute arbitrary code on a victim's system simply by convincing them to visit a malicious webpage or load a specially crafted HTML document. This does not require any user interaction beyond loading the page and typically avoids triggering security warnings if the exploit chain is sufficiently sophisticated. The ability to escape the sandbox means that subsequent attacks could potentially escalate privileges, install malware, exfiltrate sensitive data such as cookies and session tokens, or pivot into other parts of the network depending on the context in which the browser is running. Given the widespread usage of Chrome across enterprise and consumer environments, this vulnerability represents a significant risk vector for large-scale compromise campaigns targeting web-based attack surfaces.
Mitigation strategies primarily involve immediate patching to version 152.0.7977.82 or later, where Google has addressed the type checking logic within the compositing module to ensure strict adherence to expected object types during runtime operations. For organizations unable to update immediately due to compatibility constraints, deploying browser hardening policies such as disabling JavaScript execution for untrusted sites can reduce the attack surface. Additionally, utilizing endpoint detection and response solutions that monitor for anomalous memory access patterns or unexpected process behavior in renderer processes may help detect exploitation attempts in real-time. Regular security awareness training should also be emphasized to prevent users from interacting with suspicious links or downloading unknown HTML files, thereby reducing the likelihood of triggering such remote code execution vectors.