---
id: "CVE-2026-121211"
kind: "vulnerability"
aliases: ["CVE-2026-121211"]
title: "Chrome: use-after-free in PowerBookmarks lets a crafted extension run code"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "chrome", "desktop", "runtime"]
not_affected_if: ["chrome-updated", "extensions-locked-down"]
published_at: "2026-11-03T21:17:30+00:00"
first_seen_at: "2026-11-03T21:19:26+00:00"
updated_at: "2026-11-03T21:22:40+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121211", "first_seen_at": "2026-11-03T21:19:26+00:00"}]
---

# Chrome: use-after-free in PowerBookmarks lets a crafted extension run code

A use-after-free bug in the PowerBookmarks feature of Google Chrome can be chained by an attacker who already controls the renderer process and uses social engineering to get a crafted Chrome extension installed. The result is arbitrary code execution outside the browser sandbox.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Chrome version with `chrome://version` or the About page
- Review installed extensions at `chrome://extensions` for anything unexpected

## Fix

- Google Chrome: move to `157.0.8103.38` or later

## Timeline

- 2026-11-03T21:19:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121211

## From the sources

Use after free in PowerBookmarks in Google Chrome prior to 157.0.8103.38 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to execute arbitrary code outside the sandbox via a crafted Chrome extension. (Chromium security severity: High)

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_