CVE-2026-79256 Overview
CVE-2026-79256 is a sandbox escape vulnerability in the WebView component of Google Chrome on Android. The flaw stems from an externally controlled reference [CWE-610] that a remote attacker can abuse after compromising the renderer process. Exploitation requires a crafted HTML page and user interaction, but a successful attack can execute arbitrary code outside the Chrome sandbox on the underlying Android device. Google has fixed the issue in Chrome for Android version 152.0.7977.65. Chromium rates the underlying issue as Medium severity, while NVD scores the CVE as High due to the scope change and cross-boundary impact.
Critical Impact
A remote attacker who has already compromised the Chrome renderer process on Android can escape the sandbox and execute arbitrary code with WebView privileges via a crafted HTML page.
Affected Products
- Google Chrome for Android prior to 152.0.7977.65
- Google Android devices running vulnerable Chrome / WebView builds
- Android applications embedding Chrome-based WebView on affected versions
Discovery Timeline
- 2026-08-25 - CVE-2026-79256 published to NVD
- 2026-08-27 - Last updated in NVD database
Technical Details for CVE-2026-79256
Vulnerability Analysis
The vulnerability lives in the WebView component of Chrome for Android. WebView is the shared engine that renders web content inside Chrome and inside third-party Android applications. According to the advisory, the WebView code accepts an externally controlled reference that should not cross the renderer / browser trust boundary. When the renderer supplies a crafted reference, the higher-privileged process acts on it as if it were trusted.
A remote attacker who already controls the sandboxed renderer process can chain this flaw to reach code paths outside the sandbox. The result is arbitrary code execution with the privileges of the WebView host process, which typically has broader access to device APIs and user data than a sandboxed renderer.
The attack requires user interaction, such as loading a malicious page, and has high attack complexity. However, the scope changes across a trust boundary, and confidentiality, integrity, and availability impacts are all high on successful exploitation.
Root Cause
The root cause is an externally controlled reference [CWE-610] in WebView. The code trusts an identifier or handle that originates in the untrusted renderer and uses it to resolve resources or dispatch operations in a more privileged context. Without adequate validation, the renderer can steer the browser process to act on attacker-chosen targets.
Attack Vector
Exploitation begins with a crafted HTML page delivered over the network. The attacker first exploits a separate flaw to compromise the Chrome renderer, then uses this WebView issue as the sandbox-escape stage. The technical details are tracked in Chromium Issue #499007248, and the fixed build is announced in the Google Chrome Stable Update.
No public proof-of-concept or exploit code is currently available for CVE-2026-79256.
Detection Methods for CVE-2026-79256
Indicators of Compromise
- Chrome or WebView-hosting Android apps spawning unexpected child processes or writing to app-private directories after visiting an untrusted page.
- Outbound connections from WebView-embedding apps to previously unseen domains immediately after a browsing session.
- Crash traces referencing WebView renderer-to-browser IPC on Chrome versions earlier than 152.0.7977.65.
Detection Strategies
- Inventory Android endpoints for Chrome versions below 152.0.7977.65 using mobile device management (MDM) reporting.
- Correlate browser crash telemetry with subsequent process launches or file writes to detect renderer-exploitation chains.
- Hunt for Android applications that ship an outdated bundled WebView and expose sensitive intents or file access.
Monitoring Recommendations
- Enable mobile threat defense telemetry on managed Android devices and forward it to a central analytics platform for correlation.
- Monitor for anomalous permission use by WebView-hosting apps, especially access to storage, contacts, and network sockets.
- Track advisories on the Chrome Releases blog for follow-up fixes affecting WebView.
How to Mitigate CVE-2026-79256
Immediate Actions Required
- Update Google Chrome for Android to version 152.0.7977.65 or later on all managed devices.
- Update Android System WebView through Google Play to the latest available version.
- Identify third-party Android apps that bundle their own WebView build and require vendor updates.
Patch Information
Google addressed CVE-2026-79256 in the Chrome Stable channel update announced on the Chrome Releases blog. The fix is included in Chrome for Android build 152.0.7977.65. Technical tracking is available in Chromium Issue #499007248.
Workarounds
- Restrict browsing to trusted sites on unpatched Android devices until updates are applied.
- Use MDM policies to block installation or execution of Android apps that embed outdated WebView components.
- Disable or uninstall non-essential WebView-based apps on high-risk mobile endpoints until patches are deployed.
# Verify installed Chrome version on an Android device via adb
adb shell dumpsys package com.android.chrome | grep versionName
# Verify Android System WebView version
adb shell dumpsys package com.google.android.webview | grep versionName
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
