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CVE-2026-17681 is a high-severity vulnerability affecting Google Chrome on Android versions prior to 151.0.7922.72. The flaw resides in the Web Authentication component, where insufficient validation of untrusted input allows a remote attacker who has already compromised the renderer process to potentially escape the browser’s sandbox via a crafted HTML page.
To understand how this works, it’s essential to recognize Chrome’s multi-process architecture on Android. The renderer process is responsible for parsing and executing web content, including HTML, JavaScript, and CSS. This process runs inside a restrictive sandbox designed to prevent malicious web content from accessing the underlying operating system. The Web Authentication API (WebAuthn) enables web applications to perform strong authentication using public-key cryptography, typically involving hardware authenticators like security keys or platform biometrics.
The vulnerability stems from a failure to properly sanitize or validate data passed from the renderer process to the browser’s more privileged network service or system-level components during WebAuthn operations. An attacker who gains control of the renderer process—perhaps through a separate memory corruption bug—can craft malicious input that exploits this validation gap. By doing so, they can trick the browser into executing arbitrary code outside the sandbox context, effectively breaking out of the isolated environment.
The attack chain typically begins with social engineering: the victim visits a malicious website or clicks a link to a crafted HTML page. Once the page loads, it leverages the renderer compromise to deliver a payload that abuses the WebAuthn input validation flaw. Successful exploitation grants the attacker the ability to execute system-level commands, install malware, or access sensitive data stored on the device.
The Chromium security team assigned this vulnerability a High severity rating. The CVSS v3.1 base score is 9.6 (Critical), with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. This indicates a network-accessible attack with low complexity, requiring no privileges but some user interaction, and resulting in a scope change with high impact on confidentiality, integrity, and availability. The EPSS score is 0.00343, reflecting a relatively low probability of exploitation in the wild at the time of disclosure.
Patches were released in Chrome version 151.0.7922.72 for Android. Users are strongly advised to update immediately, as this vulnerability could be chained with other renderer exploits to achieve full system compromise.
DailyCVE Form:
Platform: Google Chrome Android
Version: < 151.0.7922.72
Vulnerability: Improper Input Validation
Severity: High (CVSS 9.6)
date: 2026-07-29
Prediction: 2026-07-30
What Undercode Say:
Analytics indicate that this vulnerability is part of a broader trend of sandbox escape flaws in Chromium-based browsers. The Web Authentication component, being a relatively new and complex API, has become an attractive target for attackers. The patch in version 151.0.7922.72 addresses the input validation issue by implementing stricter sanitization routines for data exchanged between the renderer and the browser’s privileged processes.
To check your Chrome version on Android, use the following ADB command:
adb shell dumpsys package com.android.chrome | grep versionName
To verify if a device is vulnerable, you can use the following script to check the installed Chrome version against the fixed version:
!/bin/bash CHROME_VERSION=$(adb shell dumpsys package com.android.chrome | grep versionName | head -n 1 | cut -d'=' -f2) FIXED_VERSION="151.0.7922.72" if [[ "$CHROME_VERSION" < "$FIXED_VERSION" ]]; then echo "Vulnerable: $CHROME_VERSION < $FIXED_VERSION" else echo "Patched: $CHROME_VERSION >= $FIXED_VERSION" fi
For enterprises managing multiple devices, the following PowerShell command can be used to query Chrome versions via MDM APIs (hypothetical example):
Get-ADComputer -Filter | ForEach-Object {
Invoke-Command -ComputerName $_.Name -ScriptBlock {
Get-ItemProperty "HKLM:\SOFTWARE\WOW6432Node\Google\Update\Clients{8A69D345-D564-463C-AFF1-A69D9E530F96}" -Name "pv" -ErrorAction SilentlyContinue
}
}
Exploit:
While no public exploit code has been released for CVE-2026-17681 as of the analysis date, the vulnerability is considered highly exploitable in theory. A typical exploit would involve:
1. Compromising the renderer process via a separate vulnerability (e.g., a use-after-free or heap buffer overflow in V8 or Skia).
2. Crafting a malicious HTML page that interacts with the Web Authentication API.
3. Sending malformed or oversized input to the WebAuthn component, triggering the validation flaw.
4. Executing shellcode or system commands outside the sandbox.
A conceptual proof-of-concept in JavaScript might look like:
// Hypothetical exploit snippet - for educational purposes only
if (navigator.credentials && navigator.credentials.create) {
const challenge = new Uint8Array(1024 1024); // Oversized challenge
const publicKey = {
challenge: challenge,
rp: { name: "Example" },
user: {
id: new Uint8Array(16),
name: "[email protected]",
displayName: "User"
},
pubKeyCredParams: [{ type: "public-key", alg: -7 }]
};
// Trigger the vulnerability
navigator.credentials.create({ publicKey: publicKey });
}
Protection:
The primary protection against CVE-2026-17681 is to update Google Chrome on Android to version 151.0.7922.72 or later. Users should enable automatic updates from the Google Play Store to ensure timely patching.
Additional protective measures include:
- Enabling Site Isolation in Chrome flags (
chrome://flags/site-isolation-trilog) to limit the impact of renderer compromises. - Using application allowlisting or mobile device management (MDM) solutions to enforce update policies.
- Deploying endpoint detection and response (EDR) tools that monitor for anomalous process behavior indicative of sandbox escape attempts.
- Educating users to avoid clicking on suspicious links or visiting untrusted websites.
For administrators, the following Group Policy Object (GPO) setting can force automatic updates:<!-- Chromium ADMX template --> <policy name="AutoUpdateCheckPeriodMinutes" class="Machine"> <enabled value="true" /> <data id="AutoUpdateCheckPeriodMinutes" value="60" /> </policy>
Impact:
Successful exploitation of CVE-2026-17681 allows an attacker to escape the Chrome sandbox on Android devices. The impact is severe:
– Full system compromise: The attacker gains the ability to execute arbitrary code with the privileges of the browser process, which on Android can lead to device-wide compromise.
– Data exfiltration: Sensitive information such as saved passwords, cookies, and local files can be accessed and exfiltrated.
– Persistence: Malware can be installed that survives browser restarts or device reboots.
– Lateral movement: On enterprise-managed devices, the attacker may use the compromised device as a pivot point to access corporate networks.
Given the CVSS score of 9.6, this vulnerability poses a critical risk to all Android users running unpatched versions of Chrome. Organizations should prioritize patching and consider blocking Chrome versions below 151.0.7922.72 from accessing corporate resources until updates are applied.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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