CVE-2026-10963: Chrome V8 Integer Overflow RCE – Sandbox Escape Vulnerability

Technical summary

CVE-2026-10963 is an integer overflow vulnerability in the V8 JavaScript engine bundled with Google Chrome versions prior to 149.0.7827.53. The flaw allows remote code execution (RCE) within the Chrome sandbox environment via malicious HTML content. The vulnerability is triggered through network delivery (AV:N), requires no special privileges (PR:N), and needs only user interaction—specifically visiting a compromised or attacker-controlled webpage (UI:R). The CVSS 3.1 vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) reflects a score of 8.8, indicating high impact on confidentiality, integrity, and availability, though the scope remains unchanged (S:U) because the compromise is contained within the sandbox.

Business impact

Successful exploitation could result in unauthorized access to sensitive data within the browser context—credentials, personal information, files accessed through Chrome extensions, or cached content. In enterprise environments where users browse untrusted content, this vulnerability poses a significant risk for data exfiltration and lateral movement if the attacker can chain the browser sandbox escape with additional exploits. Organizations with strict security posture requirements or those exposed to advanced threat actors should treat this as a priority, as browsers are common infection vectors. The financial impact depends on data classification and regulatory obligations (GDPR, HIPAA, etc.).

Affected systems

Google Chrome is the primary affected product. The vulnerability also impacts systems running Chrome on macOS, Linux, and Windows operating systems. Any deployment of Chrome version prior to 149.0.7827.53 is vulnerable. Organizations should verify the Chrome version across their user base—particularly business environments using Chrome as a standard browser or those deploying Chromium-based applications. Note that while the source data lists macOS, Linux, and Windows OS alongside Chrome as affected vendors/products, the vulnerability is fundamentally a Chrome/V8 issue; the OS listing reflects that Chrome runs on these platforms.

Exploitability

Exploitability is straightforward. An attacker needs only to craft a malicious HTML page and serve it to users, either through a compromised website, watering hole attack, phishing email, or ad injection. No user awareness or complex interaction is required—simply loading the page may trigger the vulnerability. The low attack complexity (AC:L) and network accessibility (AV:N) mean this could be weaponized at scale. As of the modification date (2026-06-17), the vulnerability is not yet listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, but this does not indicate the flaw is difficult to exploit; it reflects KEV nomination criteria and timing rather than technical difficulty.

Remediation

Immediate patching is the primary remediation: update Google Chrome to version 149.0.7827.53 or later. This patch should be deployed to all endpoints running Chrome. Additionally, consider: (1) using Chrome Enterprise features to enforce automatic updates and restrict user-level overrides, (2) deploying browser isolation technologies for high-risk users or workflows, (3) enforcing content security policies to limit the execution of untrusted scripts, and (4) monitoring for suspicious browser behavior or sandbox escape attempts. For organizations unable to patch immediately, restricting browsing to trusted, internal sites only and disabling unnecessary extensions can reduce exposure.

Patch guidance

Update Chrome to version 149.0.7827.53 or later. For enterprise deployments, use the Chrome Enterprise or Chrome for Business update mechanisms to push updates across managed devices. Verify patch application by checking Chrome's version in Settings > About Google Chrome, which will force an update check and display the installed version. Organizations should test patches in a pilot group first to ensure no compatibility issues, though V8 patches typically do not introduce breaking changes. Monitor update completion rates to identify straggler devices that may require manual intervention or reconfiguration.

Detection guidance

Detection is challenging because the exploit is JavaScript-based and executes within the browser. Monitor for: (1) anomalous process creation or network connections originating from the Chrome sandbox process (particularly data exfiltration), (2) Chrome crash logs or sandbox violation attempts in system event logs, (3) unexpected extension installations or modifications, (4) unusual CPU or memory spikes during webpage loading. Network-based detection could include rules to identify known malicious payload signatures if they are published post-disclosure. Endpoint Detection and Response (EDR) tools should be tuned to flag Chrome sandbox escapes or unusual child processes spawned by Chrome. At present, no specific indicators of compromise are widely published for this vulnerability.

Why prioritize this

This vulnerability merits urgent prioritization because: (1) CVSS 8.8 indicates high severity, (2) attack complexity is low and requires only user interaction, (3) it affects one of the most widely deployed software packages globally, (4) it enables arbitrary code execution in the browser context with potential for lateral movement, (5) no exploitation complexity or special conditions are required, and (6) users are likely unaware of the risk simply by visiting a compromised website. For security leaders, this should take precedence over lower-severity vulnerabilities. Immediate patch deployment or workaround implementation is justified.

Risk score, explained

The CVSS 3.1 score of 8.8 (High) reflects: a network attack vector (no physical presence required), low attack complexity (straightforward exploitation), no privilege escalation needed, required but simple user interaction (clicking a link), unchanged scope (sandbox confinement), and high impact across confidentiality, integrity, and availability. The score appropriately captures the combination of easy exploitation and significant potential harm. Chromium's internal severity rating of 'High' aligns with this assessment. However, practitioners should note that the sandbox mitigation partially bounds the impact—this is not an operating system-level code execution, and may be factored into risk acceptance decisions depending on organizational tolerance and data classification.

Frequently asked questions