---
id: "CVE-2026-121204"
kind: "vulnerability"
aliases: ["CVE-2026-121204"]
title: "Chrome: incomplete DevTools cleanup lets a web page bypass origin policy"
severity: "low"
cvss: null
epss: 0.00214
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "chrome", "desktop", "runtime"]
not_affected_if: ["already-updated"]
published_at: "2026-11-03T21:17:29+00:00"
first_seen_at: "2026-11-03T21:19:26+00:00"
updated_at: "2026-11-04T17:55:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121204", "first_seen_at": "2026-11-03T21:19:26+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-121204", "first_seen_at": "2026-11-04T17:55:20+00:00"}]
---

# Chrome: incomplete DevTools cleanup lets a web page bypass origin policy

Google Chrome before 157.0.8103.38 has an incomplete cleanup flaw in DevTools. A remote attacker can use a crafted HTML page to bypass web origin policy, per the Chromium security severity rating of Low.

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

## How to check

- Check the Chrome version under Chrome menu > Help > About Google Chrome, or run `google-chrome --version` on Linux.
- Compare the installed version against `157.0.8103.38`.

## 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-2026-121204
- 2026-11-04T17:55:20+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-121204

## From the sources

Incomplete cleanup in DevTools in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Low)

---

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