CVE-2026-113084 in Chrome
Summary
by MITRE • 10/21/2026
Improper input validation in Permissions in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified as an improper input validation flaw within the permissions handling subsystem of Google Chrome prior to version 156.0.8078.47 represents a significant breach in browser isolation mechanisms. This defect specifically affects how the browser processes permission requests and validates associated inputs during navigation or script execution contexts. The core technical issue stems from insufficient sanitization or boundary checking when handling data passed between different security zones, particularly those involving cross-origin interactions or dynamic content injection. By failing to rigorously validate these inputs, the application allows malformed or specially crafted data structures to bypass expected permission checks, effectively weakening the enforcement of the sandbox boundaries that are designed to contain malicious code execution within a restricted environment.
From an operational perspective, this vulnerability enables a remote attacker to execute arbitrary code outside the browser's sandbox through a meticulously constructed HTML page. The attack vector typically involves social engineering or drive-by download tactics where a victim is induced to visit a malicious website containing exploit code tailored to trigger the input validation failure. Once triggered, the flaw allows the attacker to escape the restrictive execution context of the renderer process and gain higher privileges within the operating system environment. This sandbox escape capability transforms what might otherwise be a contained script injection into a full remote code execution scenario, potentially leading to complete compromise of the user's device, including access to sensitive files, credentials, and persistent malware installation without further user interaction or consent.
This incident aligns with common vulnerability classifications such as CWE-20 Improper Input Validation and CWE-787 Out-of-bounds Write if memory corruption is involved in the exploitation chain. In terms of adversary tactics, this behavior corresponds to ATT&CK technique T1059 Command and Scripting Interpreter for initial execution and potentially T1068 Exploitation for Privilege Escalation or T1211 Exploitation for Defense Evasion if used to bypass security controls. The medium severity rating assigned by the Chromium team reflects the balance between the complexity of exploitation, which requires a crafted HTML page, and the high impact of achieving arbitrary code execution outside the sandbox.
To mitigate this risk, users must immediately update Google Chrome to version 156.0.8078.47 or later where these input validation checks have been hardened. Organizations should enforce automatic updates for all client machines to ensure timely patching against such browser-based threats. Additionally, implementing strict content security policies and disabling unnecessary JavaScript execution on untrusted sites can reduce the attack surface available to attackers attempting to leverage this vulnerability. Security monitoring tools should be configured to detect unusual process creation events originating from browser processes that attempt to spawn external executables or access restricted system resources, providing an additional layer of defense against successful exploitation attempts.