CVE-2026-12467: Google Chrome Use After Free Vulnerability

CVE-2026-12467 Overview

CVE-2026-12467 is a use-after-free vulnerability in the Extensions component of Google Chrome prior to version 149.0.7827.155. An attacker who has already compromised the renderer process can exploit this flaw to potentially escape the Chrome sandbox using a crafted HTML page. The issue is tracked under [CWE-416] (Use After Free) and affects Chrome on Windows, macOS, and Linux. Google rated the Chromium security severity as High.

Critical Impact
Successful exploitation enables a sandbox escape from a compromised renderer, allowing code execution outside Chrome's isolation boundary on the host operating system.

Affected Products

Google Chrome versions prior to 149.0.7827.155
Chrome on Microsoft Windows
Chrome on Apple macOS and Linux

Discovery Timeline

2026-06-17 - CVE-2026-12467 published to NVD
2026-06-18 - Last updated in NVD database

Technical Details for CVE-2026-12467

Vulnerability Analysis

The flaw is a use-after-free condition within Chrome's Extensions subsystem. Use-after-free occurs when code references heap memory after it has been freed, allowing an attacker to manipulate the contents of the reallocated region. In this case, the dangling reference is reachable from a compromised renderer process and provides a path across the renderer-to-browser trust boundary.

Chrome's multi-process architecture isolates untrusted web content inside a sandboxed renderer. The Extensions component, however, executes logic in the more privileged browser process and exposes interprocess communication (IPC) surfaces to renderers. A memory safety defect on that surface gives attackers a primitive suitable for sandbox escape.

Root Cause

The root cause is improper object lifetime management inside the Extensions code path. An object is destroyed while another component still holds a pointer to it, and a subsequent operation dereferences that freed memory. Attackers can groom the heap so the freed slot is reoccupied with controlled data, converting the dangling pointer into a type confusion or arbitrary read/write primitive. The bug is referenced in Chromium Issue #520202726.

Attack Vector

Exploitation is a chained scenario. The attacker first compromises the renderer through a separate bug, typically delivered by a crafted HTML page. The attacker then triggers the Extensions use-after-free via IPC messages from the compromised renderer to escape the sandbox. User interaction is required, since the victim must visit attacker-controlled content. No verified public exploit or proof-of-concept code is available for this issue. The EPSS probability is 0.217%.

No public exploit code is available. See the Google Chrome Stable Update advisory for vendor details.

Detection Methods for CVE-2026-12467

Indicators of Compromise

Chrome renderer or browser process crashes referencing the Extensions component or heap corruption signatures.
Unexpected child processes spawned by chrome.exe or the Chrome browser binary on macOS and Linux.
Outbound connections from Chrome to unfamiliar domains immediately after rendering attacker-controlled HTML.

Detection Strategies

Monitor endpoints for Chrome versions below 149.0.7827.155 and flag hosts that remain unpatched.
Alert on Chrome processes writing to disk outside expected user-profile and cache directories.
Correlate browser process crash telemetry with subsequent process creation events to surface possible sandbox escapes.

Monitoring Recommendations

Ingest Chrome crash dumps and Windows Error Reporting events into the SIEM for trend analysis.
Track parent-child process lineage from chrome.exe and equivalent binaries on macOS and Linux.
Review extension installation events and unexpected changes to extension manifests across the fleet.

How to Mitigate CVE-2026-12467

Immediate Actions Required

Update Google Chrome to version 149.0.7827.155 or later on all Windows, macOS, and Linux endpoints.
Force a Chrome restart after deployment to ensure the patched binary is loaded into memory.
Audit installed extensions and remove any that are not required or come from untrusted publishers.

Patch Information

Google released the fix in the Chrome Stable channel update documented in the Google Chrome Stable Update advisory. Administrators should validate that managed installations have updated to 149.0.7827.155 or later. Technical details are tracked in Chromium Issue #520202726.

Workarounds

Restrict extension installation through enterprise policy until patching is complete.
Apply Chrome enterprise policies to enable site isolation and block unknown extension sources.
Reduce exposure by directing users away from untrusted sites and enforcing safe browsing protections.

bash

# Verify Chrome version on Linux/macOS endpoints
google-chrome --version

# Example Chrome enterprise policy snippet (Linux JSON)
# /etc/opt/chrome/policies/managed/extensions.json
{
  "ExtensionInstallBlocklist": ["*"],
  "ExtensionInstallAllowlist": ["<approved-extension-id>"]
}