---
id: "CVE-2026-118336"
kind: "vulnerability"
aliases: ["CVE-2026-118336"]
title: "Chrome: Headless input validation flaw lets crafted HTML run code in sandbox"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser-automation", "chrome", "headless-chrome", "playwright", "puppeteer", "runtime", "self-hosted"]
not_affected_if: ["no-headless-chrome", "trusted-content-only"]
published_at: "2026-10-27T23:17:01+00:00"
first_seen_at: "2026-10-27T23:29:43+00:00"
updated_at: "2026-10-27T23:31:47+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118336", "first_seen_at": "2026-10-27T23:29:43+00:00"}]
---

# Chrome: Headless input validation flaw lets crafted HTML run code in sandbox

Improper input validation in Headless mode of Google Chrome before 156.0.8078.73 lets a remote attacker run arbitrary code inside the browser sandbox. The attack works through a crafted HTML page that a victim loads.

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

## How to check

- Run `google-chrome --version` or `chromium --version` on machines and CI runners that use Chrome in headless mode, and compare against `156.0.8078.73`.
- Check whether automation (Puppeteer, Playwright, Selenium) drives a bundled or system Chrome build that is older than `156.0.8078.73`.

## Fix

- Update Google Chrome to `156.0.8078.73` or later.
- Update the bundled Chromium in Puppeteer, Playwright or other headless tooling to a build that includes this fix.

## Timeline

- 2026-10-27T23:29:43+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118336

## From the sources

Improper input validation in Headless in Google Chrome prior to 156.0.8078.73 allowed a remote attacker to potentially execute arbitrary code inside the sandbox via a crafted HTML page. (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_