CVE-2026-103625 in Chrome
Summary
by MITRE • 10/02/2026
Type confusion in V8 in Google Chrome prior to 154.0.8037.97 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 • 10/02/2026
The vulnerability described involves a type confusion flaw within the V8 JavaScript engine, which serves as the core runtime for Google Chrome and other Chromium-based browsers prior to version 154.0.8037.97. Type confusion is a critical class of memory safety vulnerabilities where an object or variable is treated with one data type while it actually holds another. In the context of V8, this typically occurs when the engine fails to correctly track or enforce the expected types of objects during Just-In-Time (JIT) compilation or execution phases. This discrepancy allows an attacker who controls the input data to manipulate internal memory structures in unintended ways, effectively bypassing the type safety mechanisms that are fundamental to preventing arbitrary code execution within constrained environments like browser sandboxes.
From a technical perspective, this flaw likely stems from incorrect assumptions made by the JIT compiler regarding object shapes or property access patterns. When V8 optimizes JavaScript code for performance, it relies on hidden classes and inline caches to predict types at runtime. If an attacker can craft a specific sequence of operations that forces the engine into an inconsistent state where type checks are skipped or misinterpreted, they can achieve arbitrary read and write primitives. This capability is particularly dangerous because it allows the manipulation of memory addresses, function pointers, or other critical data structures within the browser process. The severity is rated as High by Chromium security teams due to the direct path this vulnerability provides from a remote vector to code execution.
The operational impact of exploiting this type confusion is severe, enabling a remote attacker to execute arbitrary code inside the sandboxed environment of Chrome. Modern browsers employ strict sandboxing models designed to isolate web content from the underlying operating system and sensitive user data. However, if an attacker can escape these constraints through memory corruption techniques facilitated by the type confusion, they gain significant privileges within the browser process. This could lead to further exploitation steps such as sandbox escapes, where the attacker breaks out of the restricted environment entirely to execute code on the host machine. Consequently, this vulnerability poses a direct threat to user confidentiality and integrity, potentially allowing for data theft, malware installation, or complete system compromise depending on subsequent exploit chain components.
This incident aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-843, which refers to Access of Incorrect Type, and often intersects with memory corruption issues like use-after-free or buffer overflows that are frequently the downstream effects of type confusion in complex engines like V8. In terms of threat modeling, this vulnerability maps to MITRE ATT&CK techniques related to Initial Execution via Web Browsers (T1204) and potentially Defense Evasion through sandbox escape if successful exploitation leads to privilege escalation within the host system. The attack vector is classified as remote because it requires only a crafted HTML page hosted on a malicious website or delivered via phishing, requiring no user interaction beyond visiting the site.
Mitigation for this vulnerability primarily involves updating Google Chrome and all Chromium-based browsers to version 154.0.8037.97 or later, where these type confusion issues have been addressed by developers through rigorous code review and fuzzing efforts. For organizations managing large fleets of endpoints, automated patch management systems should be configured to prioritize this update due to the high severity rating. Additionally, users can employ browser hardening techniques such as disabling JavaScript execution for untrusted sites or using extensions that restrict script access on suspicious domains. Security teams should also monitor network traffic and endpoint detection logs for indicators of compromise associated with exploit kits targeting V8 vulnerabilities, ensuring rapid response if any attempts are detected in the wild.