CVE-2026-13033: Google Chrome Blink RCE Vulnerability

CVE-2026-13033 Overview

CVE-2026-13033 is an out-of-bounds read and write vulnerability in the Blink>InterestGroups component of Google Chrome. The flaw affects Chrome versions prior to 149.0.7827.197 and allows a remote attacker to execute arbitrary code by serving a crafted HTML page. Chromium has classified the security severity as Critical, while the National Vulnerability Database (NVD) assigns a CVSS 3.1 base score of 8.8. The vulnerability is tracked under [CWE-125] (Out-of-bounds Read) and impacts confidentiality, integrity, and availability of the browser process.

Critical Impact
A remote attacker can achieve arbitrary code execution within the Chrome renderer process by enticing a user to load a malicious HTML page.

Affected Products

Google Chrome desktop versions prior to 149.0.7827.197
Chromium-based browsers incorporating the vulnerable Blink>InterestGroups code
All operating systems supported by the Chrome stable channel (Windows, macOS, Linux)

Discovery Timeline

2026-06-24 - CVE-2026-13033 published to NVD
2026-06-25 - Last updated in NVD database

Technical Details for CVE-2026-13033

Vulnerability Analysis

The vulnerability resides in the Blink>InterestGroups subsystem of the Chrome rendering engine. Interest Groups are part of the Protected Audience API (formerly FLEDGE), which manages advertising auction logic inside the browser. The defect permits both out-of-bounds reads and out-of-bounds writes on memory allocated by Blink. An attacker who successfully triggers the condition can corrupt adjacent heap memory and steer execution into attacker-controlled data. Exploitation requires user interaction, specifically navigation to a crafted HTML page that invokes the affected Interest Group code paths.

Root Cause

The underlying weakness is classified as [CWE-125] Out-of-Bounds Read, accompanied by an out-of-bounds write condition. The Blink component fails to enforce correct buffer boundary checks when processing Interest Group data structures. As a result, attacker-influenced indices or size values cause reads and writes past the allocated buffer, breaking memory safety invariants in the renderer.

Attack Vector

The attack is delivered over the network through a malicious or compromised web page. When the victim loads the page, JavaScript invokes the Interest Groups API in a manner that triggers the boundary violation. The crafted content drives the renderer toward a memory layout that converts the out-of-bounds primitive into arbitrary code execution. No privileges are required, but user interaction is needed to navigate to the attacker-controlled URL.

No verified public proof-of-concept code is available. Refer to the Chromium Issue Tracker Entry and the Google Chrome Update Blog for vendor technical detail as it becomes public.

Detection Methods for CVE-2026-13033

Indicators of Compromise

Chrome renderer process crashes or unexpected child process terminations correlated with browsing activity
Outbound connections from chrome.exe to newly observed or low-reputation domains immediately after a page load
Unexpected child processes spawned by the browser, particularly shells or script interpreters
Browser telemetry showing repeated invocation of Protected Audience or Interest Groups APIs from untrusted origins

Detection Strategies

Inventory Chrome installations and flag any host running a version below 149.0.7827.197
Monitor endpoint process trees for anomalous descendants of chrome.exe such as cmd.exe, powershell.exe, or bash
Inspect web proxy logs for HTML payloads referencing navigator.joinAdInterestGroup or runAdAuction from untrusted sites
Apply behavioral detections for renderer sandbox escape patterns and shellcode-like memory allocations

Monitoring Recommendations

Centralize browser version telemetry through endpoint management and SIEM dashboards
Forward Chrome crash reports and WerFault events for triage on repeated renderer faults
Alert on first-seen domains delivering large or obfuscated JavaScript bundles to high-value users
Track DNS and TLS SNI for connections initiated by browser child processes after suspicious navigations

How to Mitigate CVE-2026-13033

Immediate Actions Required

Update Chrome to version 149.0.7827.197 or later on every managed endpoint
Force-restart Chrome after deployment to ensure the patched binary is loaded into memory
Audit Chromium-derived browsers (Edge, Brave, Opera, Vivaldi) and apply vendor updates that incorporate the upstream fix
Restrict browsing to trusted sites for high-risk users until patching is verified

Patch Information

Google released the fix in the Chrome stable channel at version 149.0.7827.197. Details are published in the Google Chrome Update Blog, and the underlying issue is tracked in the Chromium Issue Tracker Entry. Administrators using enterprise deployment should push the update through Group Policy, Microsoft Intune, Jamf, or equivalent management tooling.

Workarounds

Disable the Protected Audience API through enterprise policy where business workflows permit
Apply the URLBlocklist policy to block known malicious advertising and tracking domains
Enforce Site Isolation and ensure the Chrome sandbox is not disabled by command-line flags
Use network-layer filtering to block unvetted ad exchanges and Interest Group participants until patching completes

bash

# Enterprise policy example to disable Protected Audience API on managed Chrome installs
# Linux managed policy file: /etc/opt/chrome/policies/managed/disable_fledge.json
{
  "PrivacySandboxAdMeasurementEnabled": false,
  "PrivacySandboxAdTopicsEnabled": false,
  "PrivacySandboxSiteEnabledAdsEnabled": false
}