CVE-2026-13943: Google Chrome Information Disclosure Flaw

CVE-2026-13943 Overview

CVE-2026-13943 is an uninitialized memory use vulnerability in the Cascading Style Sheets (CSS) implementation of Google Chrome on Android. The flaw exists in versions prior to 150.0.7871.47 and is classified under [CWE-457] Use of Uninitialized Variable. A remote attacker can leverage a crafted HTML page to read potentially sensitive information from Chrome's process memory. Exploitation requires user interaction, such as visiting an attacker-controlled webpage. Google's Chromium security team rated this issue as Medium severity. The vulnerability affects only confidentiality, with no direct impact on integrity or availability.

Critical Impact
A remote attacker can read uninitialized process memory from the Chrome renderer by luring an Android user to a crafted HTML page, potentially exposing sensitive in-memory data.

Affected Products

Google Chrome on Android prior to 150.0.7871.47
Google Android (as the underlying platform for Chrome mobile builds)
Chromium-based components sharing the affected CSS code path

Discovery Timeline

2026-06-30 - CVE-2026-13943 published to NVD
2026-07-02 - Last updated in NVD database

Technical Details for CVE-2026-13943

Vulnerability Analysis

The vulnerability resides in Chrome's CSS handling on Android. A code path in the CSS engine reads a variable or memory region before it has been initialized. When an attacker delivers a specially crafted HTML page that triggers this code path, the renderer processes uninitialized bytes as if they were valid style data. Those bytes may contain residual values left by previous allocations in the renderer process. The attacker can then observe side effects, such as rendered output or values reflected back through JavaScript APIs, to reconstruct memory contents. The Chromium project categorizes this under [CWE-457], which covers logic errors where memory is used without deterministic initialization.

Root Cause

The root cause is a missing initialization step in the CSS subsystem. Chrome allocates a structure or buffer used during style computation but fails to zero or otherwise assign a default value before consumption. On Android, memory layouts and allocator behavior make previously freed heap contents likely to occupy the affected region. Attackers exploit this to convert uninitialized reads into an information disclosure primitive.

Attack Vector

Exploitation is remote and requires user interaction. The victim must load an attacker-controlled or compromised HTML page in Chrome for Android. No authentication is needed. The crafted page uses specific CSS constructs to invoke the vulnerable code path and infer memory contents. Successful exploitation yields information disclosure only, but leaked pointers or tokens can support broader exploit chains against the renderer sandbox. See the Chromium Issue Tracker Entry for tracking details.

No verified proof-of-concept code is publicly available. Refer to the Google Chrome Stable Update advisory for the vendor's technical summary.

Detection Methods for CVE-2026-13943

Indicators of Compromise

Android devices running Chrome versions earlier than 150.0.7871.47 observed loading unfamiliar or newly registered domains hosting HTML with unusual inline CSS.
Renderer process crashes or anomalous memory read patterns in Chrome telemetry when parsing complex CSS from untrusted origins.
Outbound requests from mobile endpoints to URLs referenced in threat intelligence feeds tied to Chromium exploitation activity.

Detection Strategies

Inventory Chrome for Android versions across managed mobile fleets and flag any build below 150.0.7871.47.
Inspect web proxy and DNS logs for user-agent strings identifying vulnerable Chrome Android versions communicating with low-reputation domains.
Correlate mobile browsing telemetry with threat intelligence covering CVE-2026-13943 exploitation attempts.

Monitoring Recommendations

Enable continuous version compliance monitoring for Chrome on Android through mobile device management (MDM).
Alert on repeated renderer crashes reported through Chrome enterprise reporting, which may indicate exploitation attempts.
Monitor for lateral indicators such as credential reuse following mobile browsing sessions on unmanaged networks.

How to Mitigate CVE-2026-13943

Immediate Actions Required

Update Google Chrome on Android to version 150.0.7871.47 or later through the Google Play Store.
Push forced Chrome updates via MDM policies to all managed Android endpoints.
Instruct users to avoid opening untrusted links on mobile devices until patching completes.

Patch Information

Google addressed CVE-2026-13943 in Chrome Stable channel version 150.0.7871.47 for Android. Full patch details and release notes are available in the Google Chrome Stable Update advisory. Chromium-based browsers that consume the same CSS code should be updated to a build incorporating the upstream fix referenced in the Chromium Issue Tracker Entry.

Workarounds

Restrict browsing on Android to trusted sites until the patched Chrome version is deployed.
Deploy enterprise web filtering to block newly registered and low-reputation domains on mobile networks.
Disable JavaScript for untrusted origins where feasible, reducing the attacker's ability to script CSS-based memory probing.

bash

# Configuration example: enforce minimum Chrome version via Android Enterprise policy
# Managed Configuration key for Chrome on Android
{
  "MinimumChromeVersion": "150.0.7871.47",
  "URLBlocklist": ["*"],
  "URLAllowlist": ["https://*.corp.example.com"]
}