CVE-2026-11670: Google Chrome Use After Free Vulnerability

CVE-2026-11670 Overview

CVE-2026-11670 is a use-after-free vulnerability [CWE-416] in the PDF component of Google Chrome. The flaw affects Chrome versions prior to 149.0.7827.103 across Windows, macOS, and Linux. A remote attacker can execute arbitrary code inside the Chrome sandbox by serving a crafted PDF file to a victim. Exploitation requires user interaction, typically opening or rendering the malicious PDF in the browser. Google's Chromium security team rated this issue High severity. The vulnerability is patched in the stable channel update released through Chrome Releases.

Critical Impact
A crafted PDF can trigger memory corruption in Chrome's PDF renderer, allowing arbitrary code execution within the sandboxed process and providing attackers a foothold for further chained exploitation.

Affected Products

Google Chrome versions prior to 149.0.7827.103
Chrome desktop builds on Microsoft Windows, Apple macOS, and Linux
Chromium-based browsers that incorporate the vulnerable PDF component

Discovery Timeline

2026-06-09 - CVE-2026-11670 published to NVD
2026-06-09 - Last updated in NVD database

Technical Details for CVE-2026-11670

Vulnerability Analysis

The vulnerability resides in Chrome's PDF rendering component, which is built on the PDFium library. A use-after-free condition occurs when the PDF parser releases a heap object but retains a dangling pointer that is later dereferenced during continued document processing. An attacker who controls the layout and object lifetimes within a crafted PDF can reclaim the freed memory with attacker-influenced data, leading to controlled memory corruption.

Because Chrome isolates PDF rendering inside a sandboxed renderer process, successful exploitation yields code execution constrained by sandbox policies. Attackers typically chain a renderer-level flaw like this one with a separate sandbox escape to achieve full system compromise. The remote, network-reachable nature of the bug and the prevalence of inline PDF viewing make it attractive for drive-by attacks and targeted phishing.

Root Cause

The root cause is improper object lifetime management in the PDF parsing or rendering path. A reference to a heap-allocated object persists after the object is freed, and a subsequent operation dereferences that stale pointer. The Chromium issue tracker entry issue 515469283 records the underlying defect.

Attack Vector

Exploitation begins with the attacker hosting or delivering a malicious PDF. The victim opens the file by visiting a web page that embeds the PDF, by clicking a link in email or chat, or by downloading and viewing the file in Chrome. The crafted document triggers the specific allocation, free, and reuse sequence required to corrupt memory inside the renderer. Once code execution is achieved in the sandbox, attackers may pivot using a secondary vulnerability to escape isolation.

No verified public exploit code is currently available. Refer to the Chromium Issue Tracker Entry for any technical details disclosed by Google.

Detection Methods for CVE-2026-11670

Indicators of Compromise

Unexpected Chrome renderer process crashes correlated with PDF document loads
PDF files originating from untrusted domains delivered through links, ad redirects, or email attachments
Renderer processes spawning unusual child processes or initiating outbound network connections to unfamiliar hosts
Browser telemetry showing Chrome versions below 149.0.7827.103 after the patch release

Detection Strategies

Inventory installed Chrome versions across managed endpoints and flag any build older than 149.0.7827.103
Inspect web proxy and email gateway logs for PDF downloads from low-reputation domains
Hunt for renderer process anomalies such as unexpected memory allocations, crashes, or post-exploitation behaviors like credential or token access

Monitoring Recommendations

Enable centralized browser version reporting through enterprise browser management or endpoint inventory tooling
Forward endpoint process telemetry and browser crash data to a SIEM for correlation against known exploitation patterns
Monitor for outbound connections from chrome.exe child processes that deviate from baseline browsing behavior

How to Mitigate CVE-2026-11670

Immediate Actions Required

Update Google Chrome to version 149.0.7827.103 or later on all Windows, macOS, and Linux endpoints
Restart Chrome after applying the update to ensure the patched binaries are loaded
Audit Chromium-based browsers and embedded webview components for vulnerable PDFium builds and update vendor-supplied versions

Patch Information

Google has released the fix in the Chrome stable channel. Administrators should consult the Google Chrome Desktop Update advisory and roll out version 149.0.7827.103 or newer through managed update channels. Enterprise deployments using Chrome Browser Cloud Management or group policy should verify auto-update policies are enforced.

Workarounds

Disable the built-in Chrome PDF viewer via the AlwaysOpenPdfExternally enterprise policy and route PDFs to a hardened, patched reader until updates complete
Block or quarantine PDF attachments from external senders at the email gateway pending patch deployment
Restrict execution of Chrome to users on patched builds through application allowlisting where feasible

bash

# Configuration example: enforce external PDF handling via Chrome enterprise policy on Linux
sudo tee /etc/opt/chrome/policies/managed/disable_pdf_viewer.json > /dev/null <<EOF
{
  "AlwaysOpenPdfExternally": true
}
EOF