CVE-2026-106203 in Chrome
Summary
by MITRE • 10/06/2026
Incomplete cleanup in Autofill in Google Chrome on on iOS prior to 155.0.8059.39 allowed a remote attacker leveraging social engineering to obtain sensitive information via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as an incomplete cleanup issue within the Autofill functionality of Google Chrome on iOS prior to version 155.0.8059.39 represents a significant data exposure risk rooted in improper state management during user interaction flows. This flaw specifically affects the browser's ability to correctly clear or isolate sensitive input fields after they have been populated by the autofill mechanism, particularly when navigating between different web pages or closing tabs. The core technical deficiency lies in the persistence of previously entered personal information within memory buffers or UI components that are not fully reset upon page unload or context switch. This allows residual data to remain accessible in a manner that bypasses standard privacy expectations and security boundaries implemented by the browser engine, creating an opportunity for unauthorized access to confidential user details such as names, addresses, payment card numbers, or authentication credentials stored locally on the device.
From an operational perspective, this vulnerability is primarily exploitable through social engineering tactics rather than direct code execution or remote command injection. An attacker would need to craft a malicious HTML page designed to trigger specific browser behaviors that expose these lingering autofill values. For instance, such a crafted page might utilize JavaScript techniques to inspect the DOM state of input fields during rapid navigation sequences or tab switching events where the cleanup routine fails to execute completely. By leveraging this timing window and the incomplete reset mechanism, an attacker can programmatically retrieve sensitive data that was previously entered by the user into other sites but remains visible in the current context due to the bug. This effectively turns a convenience feature intended to streamline web interactions into a vector for credential harvesting or identity theft without requiring any additional plugins or exploits beyond standard browser capabilities and user interaction with malicious content.
The security severity of this issue is classified as High by Chromium, reflecting its potential impact on individual privacy and financial security. The attack complexity is considered low because it relies heavily on social engineering to lure users into visiting the crafted page, but once there, the exploitation does not require sophisticated technical skills or elevated privileges. This aligns with common patterns seen in web-based data exfiltration attacks where trust in browser defaults is manipulated against the user. The lack of proper isolation between different browsing contexts allows cross-site information leakage that violates the principle of least privilege and expected sandboxing behavior, even though it does not directly compromise the underlying operating system or allow arbitrary code execution.
Mitigation strategies for this vulnerability focus primarily on software updates and behavioral precautions. Users must upgrade Google Chrome to version 155.0.8059.39 or later on iOS devices immediately upon availability, as these versions contain patches that enforce stricter cleanup protocols for autofill data during navigation events. In the interim, users should exercise caution when visiting untrusted websites and consider disabling autofill features for sensitive fields such as credit card numbers if not strictly necessary. Additionally, enabling private browsing modes can help mitigate exposure by preventing the storage of history and form data in persistent memory structures that might be susceptible to this specific cleanup failure. Security awareness training emphasizing the risks of interacting with suspicious links remains a critical complementary defense layer against social engineering attempts designed to exploit such browser-side logic flaws.
This vulnerability maps directly to CWE-209, which describes the generation of an error message that reveals sensitive information, although in this case it is more accurately categorized under CWE-358: Improperly Implemented Security Check for Sensitive Data or CWE-614: Sensitive Cookie in Incorrect Context if viewed through the lens of session state leakage. Furthermore, from a tactical perspective within the MITRE ATT&CK framework, this exploit aligns with T1059.007: JavaScript and potentially falls under data exfiltration techniques where information is gathered from local systems before being sent to external command and control infrastructure via crafted web requests. The incomplete cleanup serves as an enabler for these broader attack chains by providing the initial access vector to sensitive user inputs that would otherwise be protected by standard browser isolation mechanisms.