CVE-2026-106321 in Chrome
Summary
by MITRE • 10/06/2026
Information leak in Editing in Google Chrome prior to 155.0.8059.39 allowed a remote attacker leveraging social engineering to leak sensitive information via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an information leak within the editing components of Google Chrome, specifically affecting versions prior to 155.0.8059.39, represents a significant risk to user privacy and data integrity. This flaw resides in the browser's handling of contenteditable regions or related input mechanisms, where improper state management or memory isolation allows sensitive contextual information to be exposed beyond its intended scope. The severity is classified as medium by Chromium security standards, indicating that while exploitation requires specific conditions, the potential for unauthorized data access is substantial and impactful for end-users relying on web-based applications for critical tasks.
The technical nature of this flaw involves a failure in the browser's internal boundaries when processing user input or rendering editable content. When a webpage utilizes crafted HTML structures to manipulate these editing interfaces, it can trigger conditions where previously cleared or isolated data remains accessible in memory buffers that are not properly sanitized before being exposed to subsequent script execution contexts. This allows an attacker who controls a malicious web page to read back information that should have been discarded or kept private during the editing process. The vulnerability exploits the complex interaction between JavaScript engines and rendering pipelines, where race conditions or logic errors permit access to internal state variables that contain sensitive user data such as form inputs, clipboard contents, or previously entered text fields.
Exploitation of this vulnerability relies heavily on social engineering tactics due to its remote nature. An attacker must lure a victim into visiting a specially crafted HTML page designed to trigger the information leak mechanism. Once the victim interacts with the malicious content, potentially by clicking elements or allowing scripts to run in an editable context, the browser inadvertently exposes sensitive data back to the attacking script. This could include personal identifiable information, authentication tokens stored temporarily during form submissions, or other confidential text that users assume is secure within their local browsing session. The reliance on social engineering means that technical controls alone are insufficient; user awareness and cautious interaction with untrusted web content remain critical defenses against this type of attack.
From a classification perspective, this vulnerability aligns closely with CWE-200, which covers Information Exposure, specifically detailing scenarios where sensitive information is disclosed to unauthorized actors through improper handling or exposure mechanisms. It also relates to the ATT&CK technique T1537, which involves transferring data from an affected system via alternative protocols or methods not typically used for such transfers, although in this case, it manifests as a direct script-based exfiltration of local browser state rather than network protocol abuse. The impact is primarily focused on confidentiality, compromising the trust users place in their web browsers to isolate and protect session-specific data from malicious scripts hosted on third-party sites.
Mitigation strategies for this vulnerability are twofold, involving both immediate patching and long-term architectural improvements. Users must update Google Chrome to version 155.0.8059.39 or later immediately upon availability, as the vendor has addressed the underlying logic errors in the editing subsystem that permitted the information leak. For organizations deploying browsers at scale, enforcing automatic updates through group policy or mobile device management solutions ensures rapid remediation across all endpoints. Additionally, developers of web applications should implement strict Content Security Policy directives to restrict inline script execution and limit access to sensitive DOM properties, thereby reducing the attack surface even if browser vulnerabilities persist. Regular security audits focusing on input handling in rich text editors can also help identify similar logic flaws before they are exploited in production environments.