CVE-2026-12466 Overview
CVE-2026-12466 is a heap buffer overflow vulnerability in the WebRTC component of Google Chrome on Windows. The flaw affects Chrome versions prior to 149.0.7827.155. A remote attacker can exploit the issue by serving a crafted HTML page to a target user. Successful exploitation allows arbitrary code execution within the browser process context. Chromium classifies the security severity as High, and the CWE designation is [CWE-122] Heap-based Buffer Overflow.
Critical Impact
Remote attackers can execute arbitrary code on Windows hosts running vulnerable Chrome builds by luring users to a malicious web page that abuses WebRTC.
Affected Products
- Google Chrome on Windows prior to 149.0.7827.155
- Microsoft Windows (host operating system for affected Chrome builds)
- Chromium-based components that embed the affected WebRTC code path
Discovery Timeline
- 2026-06-17 - CVE-2026-12466 published to NVD
- 2026-06-18 - Last updated in NVD database
Technical Details for CVE-2026-12466
Vulnerability Analysis
The vulnerability resides in the WebRTC implementation shipped with Google Chrome. WebRTC handles real-time audio, video, and data channel processing directly from untrusted network sources. A heap buffer overflow in this component allows an attacker to write beyond the bounds of an allocated heap buffer. Because WebRTC parses attacker-controlled media and signaling data, a crafted HTML page can reach the vulnerable code without user interaction beyond visiting the site. The flaw can corrupt adjacent heap structures, including object metadata and function pointers, enabling control-flow hijacking. Exploitation yields code execution within the Chrome renderer or related process, which an attacker can chain with a sandbox escape for full system compromise. The vulnerability requires user interaction limited to loading the malicious page.
Root Cause
The root cause is a heap-based buffer overflow [CWE-122] in WebRTC code paths that process attacker-controlled input. Insufficient bounds validation during buffer handling allows data to exceed the allocated region on the heap.
Attack Vector
The attack vector is network-based. An attacker hosts a crafted HTML page that initiates WebRTC operations against the victim's browser. When the user visits the page, the vulnerable code path processes attacker-supplied data and triggers the overflow. No authentication is required.
No verified public exploit code is available. Refer to the Chromium Issue Tracker Entry for additional technical context once access restrictions are lifted.
Detection Methods for CVE-2026-12466
Indicators of Compromise
- Chrome renderer or GPU process crashes referencing WebRTC modules shortly after visiting an untrusted page
- Outbound WebRTC signaling or STUN/TURN traffic to unfamiliar infrastructure preceding suspicious child process creation under chrome.exe
- Unexpected child processes spawned by chrome.exe on Windows endpoints running builds older than 149.0.7827.155
Detection Strategies
- Inventory Chrome installations and flag any Windows host running a version below 149.0.7827.155
- Hunt for browser process anomalies such as memory access violations in chrome.exe correlated with WebRTC DLL loads
- Correlate web proxy logs with endpoint telemetry to identify users who visited unknown sites immediately before browser crashes
Monitoring Recommendations
- Enable browser crash reporting and forward dumps to a centralized analysis pipeline
- Monitor for post-exploitation behaviors such as credential access, LSASS interaction, or persistence created by child processes of chrome.exe
- Track WebRTC peer connection establishment to destinations outside sanctioned collaboration platforms
How to Mitigate CVE-2026-12466
Immediate Actions Required
- Update Google Chrome on all Windows endpoints to version 149.0.7827.155 or later
- Restart Chrome after updating so the patched binary is loaded into memory
- Apply the same update to Chromium-based browsers and embedded WebViews that share the affected code
Patch Information
Google released the fix in the Chrome stable channel update referenced in the Google Chrome Desktop Update advisory. Administrators should validate that managed deployments receive 149.0.7827.155 or newer through enterprise update mechanisms.
Workarounds
- Block access to untrusted sites that initiate WebRTC sessions via enterprise web filtering until patches are deployed
- Disable WebRTC where business workflows allow, using enterprise policy controls for Chrome on Windows
- Restrict outbound STUN/TURN traffic from user subnets to approved collaboration providers
# Configuration example: enforce minimum Chrome version via Windows Group Policy registry
reg add "HKLM\Software\Policies\Google\Chrome" /v TargetVersionPrefix /t REG_SZ /d "149.0.7827.155" /f
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
