CVE-2026-79146 in Chrome
Summary
by MITRE • 08/26/2026
Information leak in CustomTabs in Google Chrome on on Android prior to 152.0.7977.65 allowed a local attacker to obtain cross-origin data via a co-installed app. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an information leak within the CustomTabs component of Google Chrome for Android represents a significant breach in browser isolation mechanisms, specifically affecting versions prior to 152.0.7977.65. This flaw allows a local attacker who has installed a malicious application on the same device to extract sensitive cross-origin data from the user's browsing session. The core of this issue lies in how Chrome handles inter-process communication and state management when interacting with third-party applications via CustomTabs, which are designed to allow apps to open web pages within a customized browser frame without fully launching the main Chrome application. When an app utilizes CustomTabs, it establishes a connection that can inadvertently expose internal states or data structures if proper sanitization and isolation checks are not rigorously enforced during the handshake and subsequent interactions between the host application and the browser process.
From a technical perspective, this vulnerability is classified under CWE-200: Information Exposure, as it results in the unauthorized disclosure of information to an actor that should not have access to it. The attacker leverages their position within the Android operating system's permission model by co-installing a malicious app with legitimate applications or user data. By exploiting specific APIs or intent filters associated with CustomTabs, the malicious application can trigger actions that cause Chrome to reveal cross-origin cookies, local storage contents, or session identifiers intended for other domains. This breaks the fundamental web security principle of same-origin policy, which is designed to prevent one origin from accessing resources belonging to another. The severity is rated as Medium by Chromium because while it does not allow direct code execution on the device, the ability to steal sensitive authentication tokens and personal data can lead to account takeover or further social engineering attacks against the victim.
The operational impact of this vulnerability extends beyond simple data theft; it undermines user trust in mobile browsing security and facilitates sophisticated phishing campaigns. An attacker who obtains cross-origin session cookies can impersonate a legitimate user on specific websites, potentially accessing private messages, financial records, or administrative panels without needing to know the user's password. This is particularly dangerous because many users reuse passwords across multiple services, meaning that compromising one high-value account could lead to broader compromise of personal and professional digital identities. Furthermore, since the attack vector requires a co-installed app, it targets devices where users may have installed potentially untrusted applications or where malware has already gained foothold through other means such as sideloading or exploiting less secure apps.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later on Android devices, which includes patches that enforce stricter isolation between CustomTabs instances and the main browser process, ensuring that cross-origin data is not inadvertently exposed through inter-app communication channels. Users should also exercise caution when installing applications from unknown sources and regularly review app permissions to minimize the attack surface available to potential local attackers. From a developer standpoint, implementing robust input validation and avoiding unnecessary exposure of internal state during CustomTabs interactions can prevent similar issues in future implementations. Security researchers and enterprise administrators are advised to monitor for updates via official Google channels and ensure that mobile device management policies enforce up-to-date browser versions across all corporate-owned or managed devices to maintain the integrity of web-based authentication mechanisms.