CVE-2026-11173: Chrome V8 Out-of-Bounds Write Sandbox Escape – Patch Guidance

Technical summary

CVE-2026-11173 is an out-of-bounds write vulnerability (CWE-787) in the V8 JavaScript engine bundled with Google Chrome prior to version 149.0.7827.53. The flaw allows an attacker with renderer-process code execution to bypass Chrome's sandbox through a crafted HTML payload, achieving full arbitrary code execution within the sandbox context. The vulnerability was assigned a CVSS 3.1 score of 8.8 (HIGH severity) due to the network attack vector, low complexity, lack of privilege requirements, and user interaction (visiting a malicious page). Chromium's internal assessment rated it as Medium severity, reflecting the prerequisite renderer compromise.

Business impact

For organizations whose users access untrusted or semi-trusted websites, this vulnerability represents a sandbox escape risk. If a renderer process is already compromised (through a separate attack vector such as a logic bug in a browser extension, a prior code-execution flaw, or user credential theft), this flaw enables lateral privilege escalation to the host system. The practical impact depends on whether the renderer is already under attacker control; as a standalone entry point, it requires user interaction and prior compromise. Affected deployments on Windows, macOS, and Linux systems should prioritize patching to eliminate this escalation path.

Affected systems

Google Chrome versions prior to 149.0.7827.53 are directly vulnerable. The vulnerability also affects systems running Chrome on Windows, macOS, and Linux kernels, since the V8 engine is bundled in all Chrome builds. Any system with an unpatched Chrome browser installation—whether user-facing or embedded in another application—is at risk if the renderer process is compromised. Third-party applications that embed Chromium (such as Electron-based apps) may also be affected depending on the version of Chromium they include.

Exploitability

Exploitability requires two conditions: (1) the attacker must first compromise the Chrome renderer process through a separate vulnerability or attack, and (2) the user must visit or be redirected to a malicious HTML page. The vulnerability itself does not require elevated privileges or special browser configurations, but the sandbox-escape nature means it is typically chained with other exploits rather than used as a primary attack vector. No public exploit code or active in-the-wild exploitation has been confirmed as of the modification date; it does not appear on the KEV catalog. However, the combination of high CVSS score and sandbox-escape capability makes it a priority for threat actors seeking multi-stage attack chains.

Remediation

Users and administrators should update Google Chrome to version 149.0.7827.53 or later. Chrome's automatic update mechanism should deploy the patch; verify the update by navigating to chrome://settings/help and confirming the version number. For organizations managing Chrome deployments via policy (Windows Group Policy, macOS profiles, or enterprise chromebook management), ensure device policy configurations enforce the minimum version requirement. Verify patching across all endpoints, including developer machines and kiosk/embedded systems running Chrome.

Patch guidance

Google Chrome releases updates automatically and typically rolls them out over several days. To expedite patching: (1) manually trigger an update check at chrome://settings/help; (2) restart the browser to complete installation; (3) confirm the version matches or exceeds 149.0.7827.53. For enterprise environments, use Chrome's policy templates (google.com/chrome/management) to set MinimumChromeVersion to 149.0.7827.53 or higher. Test patches in a non-production environment first if managing large user populations. For Linux users, verify your distribution's Chrome package is updated (snap, flatpak, or native package manager) and is at or above the patched version.

Detection guidance

Monitor Chrome crash logs and renderer process terminations for anomalous memory access patterns or segmentation faults, which may indicate exploitation attempts. Security tools with memory-access violation detection (EDR solutions with kernel-mode visibility) should flag out-of-bounds write attempts in V8. Log and alert on suspicious HTML file downloads or redirects to unsigned/untrusted origins combined with subsequent Chrome renderer crashes. Review audit logs for post-compromise lateral movement or privilege escalation following renderer process compromise. Intrusion detection systems may detect related exploit chains if they include reconnaissance or lateral-movement stages.

Why prioritize this

Although Chromium's internal assessment rated this as Medium severity, the CVSS 3.1 score of 8.8 reflects the combination of network accessibility, user-interaction requirement, and sandbox-escape capability. Prioritize patching because: (1) sandbox escapes eliminate Chrome's primary security boundary, (2) the vulnerability can be chained with other Chrome exploits to form a complete attack chain, (3) Windows, macOS, and Linux users are all at risk, and (4) automatic updates may not deploy immediately to all users. Organizations with high-value targets or environments exposed to advanced threats should patch proactively rather than waiting for evidence of active exploitation.

Risk score, explained

The CVSS 3.1 score of 8.8 (HIGH) reflects: Attack Vector: Network (AV:N)—the vulnerability can be triggered via a crafted webpage; Attack Complexity: Low (AC:L)—exploitation is straightforward once renderer access is achieved; Privileges Required: None (PR:N)—no special privileges are needed to trigger the flaw; User Interaction: Required (UI:R)—the user must visit a malicious page; Scope: Unchanged (S:U)—impact is limited to Chrome's sandbox; Confidentiality, Integrity, Availability all High (C:H/I:H/A:H)—successful exploitation allows arbitrary code execution. The score is not artificially inflated; however, note that it assumes the renderer is already compromised, which is a critical prerequisite often downplayed by the CVSS vector alone.

Frequently asked questions