CVE-2026-11003: Chrome WebRTC Use-After-Free Remote Code Execution – CVSS 8.8

Technical summary

CVE-2026-11003 is a use-after-free (CWE-416) in Chrome's WebRTC implementation. The vulnerability occurs when the browser fails to properly manage memory references during WebRTC session teardown or state transitions. An attacker can craft a specially designed HTML page that triggers premature deallocation of a WebRTC object while still holding active pointers to it. Subsequent operations on those stale pointers lead to out-of-bounds memory access, enabling code execution within the Chrome sandbox. The attack requires no authentication or special privileges, only user interaction (clicking a link or visiting a page).

Business impact

Organizations where users rely on Chrome for web-based collaboration, video conferencing, or communication—particularly those using WebRTC-enabled platforms—face elevated risk. Successful exploitation could allow an attacker to steal session tokens, exfiltrate clipboard data, or escalate to system-level compromise if combined with a secondary sandbox escape. While sandbox containment limits direct OS impact, it does not prevent theft of sensitive in-browser data or credential harvesting. Companies with strict data handling requirements should treat this as a prompt patching priority.

Affected systems

The vulnerability affects Google Chrome across Windows, macOS, and Linux systems running versions prior to 149.0.7827.53. The source data indicates exposure spans Windows (Microsoft), macOS (Apple), and Linux systems. Any user or automated system running an older Chrome version is at risk if they visit an attacker-controlled or compromised website.

Exploitability

Exploitability is high in practical terms. No special browser configuration, plugins, or user permissions are required. An attacker needs only to host a malicious HTML page and social-engineer or watering-hole a victim into visiting it. The user interaction requirement (visiting a page) is trivial in real-world scenarios. No patch bypass or advanced techniques are necessary; the vulnerability is directly triggerable via crafted HTML. CISA has not yet flagged this on the Known Exploited Vulnerabilities (KEV) catalog, but the simplicity of delivery and the high CVSS score suggest security teams should expect exploitation attempts as awareness spreads.

Remediation

Update Google Chrome to version 149.0.7827.53 or later immediately. For enterprise environments, enforce automatic updates or deploy the patched version via your standard software distribution mechanism. Users on macOS and Linux should also prioritize this update. There is no known workaround that eliminates the risk entirely; patching is the only reliable mitigation. Consider temporarily restricting access to untrusted websites if patching cannot be completed within your change window.

Patch guidance

Deploy Chrome version 149.0.7827.53 or later across all affected systems. Most users on the stable channel will auto-update, but verify completion, especially for machines with auto-update disabled or on restricted networks. Check Settings > About Google Chrome to confirm current version. For enterprises, push updates through your patch management system (e.g., WSUS, Jamf, or MDM). Test compatibility with any mission-critical web applications that rely on WebRTC, though the fix is internal and should not break legitimate applications.

Detection guidance

Monitor Chrome process execution and memory behavior for signs of WebRTC-related crashes or unusual code execution within the chrome sandbox. EDR/XDR platforms should flag processes spawned from chrome.exe/Chromium with unexpected parent-child relationships or PPID spoofing. Network-side detection is limited but look for traffic patterns consistent with delivering malicious web pages (unusual HTML payload sizes, script injection indicators). Check browser history and access logs for visits to unknown or suspicious domains around the time of any suspected compromise. Successful exploitation may leave artifacts in Chrome's crash reports (chrome://crashes) or system event logs.

Why prioritize this

This vulnerability merits immediate remediation despite not yet appearing on the KEV catalog. The combination of high CVSS (8.8), ease of exploitation (network + minimal UI), and broad user base affected makes it a top-tier threat. Use-after-free bugs in memory-unsafe code are well-understood attack primitives, and WebRTC's real-time communication nature makes it a valuable target for attackers seeking to compromise business users or steal call/meeting data. The sandbox mitigation reduces but does not eliminate risk—exfiltration of session tokens or credentials is still feasible.

Risk score, explained

The CVSS 8.8 HIGH score reflects: (1) Network-based attack vector requiring no special access; (2) low attack complexity with straightforward exploitation via HTML; (3) user interaction required but minimal (visiting a webpage); (4) high impact on confidentiality, integrity, and availability within the sandbox context; (5) sandbox scope does not lower the score because out-of-bounds memory access can leak or corrupt sensitive process data. The Chromium project's internal 'Medium' severity likely reflects confidence in sandbox isolation; however, CVSS scoring correctly elevates this to HIGH due to the practical attack surface and data-at-risk.

Frequently asked questions