---
id: 5568
title: "How an Omitted Write Barrier in V8 Turns Into RCE in Chrome: CVE-2026-5865"
cve: CVE-2026-5865
cvss: 8.8
severity: high
source_domain: nebusec.ai
source_url: "https://nebusec.ai/research/v8-maglev-incorrect-phis-untagging/"
published_at: "2026-05-07T00:00:00Z"
tags: ["rce", "browser-security", "v8", "chrome", "nebusec", "maglev", "cve-2026-5865", "write-barrier"]
phying_url: "https://phying.com/item/5568"
lang: en
---

# How an Omitted Write Barrier in V8 Turns Into RCE in Chrome: CVE-2026-5865

## Summary

NebuSec explains CVE-2026-5865: an omitted write barrier in V8's Maglev compiler lets the garbage collector miss an object, yielding fakeobj and RCE against Chrome.

## Intelligence Metadata

- **Sources:** nebusec.ai
- **CVE:** CVE-2026-5865
- **CVSS:** 8.8
- **Published:** 2026-05-07T00:00:00Z
- **Original:** https://nebusec.ai/research/v8-maglev-incorrect-phis-untagging/
- **Phying News:** https://phying.com/item/5568