CVE-2026-93387 in Chrome
Summary
by MITRE • 09/18/2026
Improper state validation in Skia in Google Chrome prior to 153.0.8010.52 allowed a remote attacker to obtain cross-origin data via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified as an improper state validation flaw within the Skia graphics library, which is integrated into Google Chrome prior to version 153.0.8010.52, represents a significant breach in browser-level isolation mechanisms. This issue stems from a logical error where the application fails to adequately verify or reset internal states during specific rendering operations involving cross-origin resources. When an attacker constructs a malicious HTML page that triggers these specific graphical processing paths, they can exploit the inconsistent state management to bypass same-origin policy restrictions. The core technical flaw lies in the failure of Skia to properly validate context boundaries before executing drawing commands on canvas elements or other graphical surfaces that may contain data from different origins. This oversight allows an attacker to read sensitive information such as cookies, local storage contents, or DOM properties belonging to a victim's active session on a trusted website, effectively achieving cross-origin data theft through visual side-channeling or direct memory access depending on the specific implementation details of the exploit vector.
From a classification perspective, this vulnerability aligns with CWE-20 Improper Input Validation and more specifically relates to CWE-359 Exposure of Private Personal Information if sensitive user data is exfiltrated. In terms of offensive security frameworks, it maps directly to MITRE ATT&CK technique T1005 Data from Local System as well as the broader category of browser-based attacks often associated with cross-site scripting or clickjacking variants where state manipulation facilitates unauthorized access. The severity rating of High by Chromium is justified because successful exploitation does not require user interaction beyond visiting a malicious webpage, and it compromises the fundamental trust model of web browsers which relies on strict separation between content from different origins.
The operational impact of this vulnerability extends beyond simple data leakage; it undermines the integrity of secure browsing environments used for financial transactions, corporate communications, and personal identity management. An attacker leveraging this flaw could potentially conduct session hijacking by stealing authentication tokens or perform targeted phishing campaigns with higher fidelity by displaying accurate content from legitimate sites while injecting malicious overlays. Furthermore, because Skia is a foundational component used across multiple platforms including Android and desktop operating systems, the implications are widespread affecting not just Chrome users but potentially other applications relying on similar graphics processing logic if they share underlying codebases or libraries.
Mitigation strategies primarily involve immediate patching to version 153.0.8010.52 or later where these state validation checks have been reinforced. Developers should ensure that all graphical contexts are properly isolated and that any operations involving cross-origin data undergo rigorous sanitization and permission verification before rendering. Security teams should monitor for unusual network traffic patterns indicative of exfiltration attempts and enforce strict Content Security Policies to limit the ability of scripts to access sensitive DOM elements or storage APIs. Regular audits of third-party libraries like Skia are essential to maintain a robust security posture against evolving browser-based attack vectors that exploit subtle logic errors in complex software systems.