Chrome V8 code execution in sandbox (CVE-2026-7899)

Vendor-confirmed - CVE-2026-7899 is a high out-of-bounds read/write in Google Chrome V8 prior to 148.0.7778.96 that lets a remote attacker execute arbitrary code inside the browser sandbox via a crafted HTML page. Patched in Chrome 148.0.7778.96 - update immediately.

Overview

CVE-2026-7899 affects the V8 JavaScript engine in Google Chrome versions before 148.0.7778.96. The vulnerability is an out-of-bounds read and write condition that occurs when V8 processes specific JavaScript constructs embedded in a web page.

An attacker can exploit this issue by hosting a malicious webpage or injecting crafted HTML into a legitimate site that a victim visits. When the target opens the page in an affected Chrome version, the out-of-bounds access can corrupt heap memory, enabling arbitrary code execution. However, the exploit runs within Chrome’s sandbox, which limits file system, network, and system-level access compared to full system compromise.

Impact

Successful exploitation gives the attacker arbitrary code execution inside Chrome’s sandboxed process. This means the attacker can:

• Read and write browser memory.
• Steal session cookies, credentials, and autofill data.
• Interact with other browser pages and extensions.
• Perform actions as the logged-in user on visited websites.

The sandbox prevents direct escalation to the operating system kernel, but combined with a separate sandbox escape, the attacker could fully compromise the host system. The CVSS 8.8 severity reflects the low complexity of exploitation and network attack vector, weighed against the requirement for user interaction (visiting a page).

Remediation and Mitigation

Google released Chrome 148.0.7778.96 to address this vulnerability. Apply the update immediately through Chrome’s built-in update mechanism or by downloading from chrome.google.com. Enterprise administrators should push the update via Chrome Browser Cloud Management or group policies.

If immediate patching is not possible:

• Disable JavaScript execution in untrusted contexts (though this breaks many websites).
• Use browser extensions that block script execution on unknown sites.
• Restrict browsing to only administratively approved websites until the patch is applied.

CISA has not confirmed active exploitation of this vulnerability as of publication. However, advisories for similar V8 out-of-bounds issues often lead to PoC code release within days. Treat this as a “Patch Now” priority.

Security Insight

CVE-2026-7899 is the latest in a recurring pattern of high-severity V8 out-of-bounds vulnerabilities that have plagued Chrome for years. While Google’s sandbox mitigates the immediate risk of full system compromise, each such bug increases the exploit chain surface for attackers who bundle them with sandbox escapes. The fact that this issue was discovered internally (no evidence of exploit in the wild suggests responsible disclosure or fuzzing) indicates Google’s testing infrastructure catches many, but not all, V8 memory safety flaws. Organizations should supplement auto-update with active browser version monitoring.

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Further Reading

• Weekly Threat Roundup: Apache & cPanel Zero-Days (Apr 27 - May 3)
• SAP npm packages compromised in credential-stealing att
• TeamPCP Supply Chain Campaign: Update 008 - 26-Day Paus
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