CVE-2026-113203 in Chrome
Summary
by MITRE • 10/21/2026
Use after free in CSS in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially execute arbitrary code inside 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 a use-after-free condition within the Cascading Style Sheets engine of Google Chrome prior to version 156.0.8078.47 represents a critical memory safety flaw that undermines the browser's integrity and isolation mechanisms. This specific class of error occurs when the application continues to reference a memory block after it has been freed, leading to undefined behavior that can be exploited by malicious actors. In the context of web browsers, such flaws are particularly dangerous because they reside within components responsible for rendering visual content, which is often triggered by user interaction with untrusted websites. The Chromium security team classified this issue as medium severity, indicating a balance between exploitability and impact, yet it remains significant due to its potential to bypass sandbox restrictions when properly chained or leveraged correctly.
From a technical perspective, the flaw resides in how Chrome manages memory allocation for CSS objects during page rendering. When an HTML page is processed, various style rules are parsed and applied to DOM elements. If the lifecycle of these internal data structures is not strictly managed, it is possible for a reference to become dangling while still being accessed by another part of the engine. This typically happens in scenarios involving dynamic content manipulation where objects are deleted or recycled before all references to them are cleared. An attacker can craft an HTML page that triggers this race condition or state inconsistency through specific sequences of style updates and DOM modifications, causing the browser to read from or write to freed memory regions.
The operational impact of this vulnerability is severe because it allows for potential arbitrary code execution within the sandboxed environment where Chrome operates modern web content. Sandboxing is a fundamental security architecture designed to limit the damage that compromised processes can cause by restricting their access to system resources and other browser tabs. However, use-after-free vulnerabilities provide attackers with primitives such as arbitrary read or write capabilities over memory contents. By carefully crafting heap layouts and exploiting these memory corruption issues, an attacker can achieve control flow hijacking, leading to the execution of malicious payloads on the victim's machine. This effectively breaks the isolation model that protects users from malicious websites, potentially resulting in full system compromise depending on the privileges under which the browser is running.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-416, which describes use after free errors where a pointer references memory it should not and actions are performed using that pointer. In terms of offensive security frameworks, this exploit path corresponds to techniques found in the MITRE ATT&CK catalog, specifically those related to exploitation for privilege escalation or defense evasion within browser-based attacks. Attackers often utilize such vulnerabilities as part of drive-by download campaigns where no user interaction beyond visiting a webpage is required. The ability to execute code inside the sandbox elevates this from a mere denial-of-service risk to a critical security breach with significant data exfiltration and persistence implications for end-users.
Mitigation strategies primarily involve updating Google Chrome to version 156.0.8078.47 or later, where these memory management issues have been addressed by the Chromium development team through rigorous code reviews and fuzzing efforts. Organizations should enforce automated patch management policies to ensure that all endpoints are running supported versions of web browsers. Additionally, users can employ browser hardening techniques such as disabling JavaScript on untrusted sites or using extensions that restrict script execution in specific contexts to reduce the attack surface. Security teams should also monitor for indicators of compromise associated with known exploit kits targeting this vulnerability class and maintain strict control over user privileges to minimize the impact if a breach occurs despite preventive measures.