# Puppeteer v25.9.0 rolls Firefox 154.0 and Chrome 152.0, adds shadow root support in MutationPoller

> Puppeteer released version 25.9.0 of puppeteer-core, updating browser versions and adding support for shadow roots in MutationPoller and tool execution cancellation in webmcp.

- Canonical: https://extractfeed.io/story/puppeteer-v25-9-0-rolls-firefox-154-0-and-chrome-152-0-adds-1dc060c/
- JSON: https://extractfeed.io/api/v1/stories/puppeteer-v25-9-0-rolls-firefox-154-0-and-chrome-152-0-adds-1dc060c.json
- Beat: Open Source & Tooling · Evidence: Primary source · Type/significance: release/2 · First seen: 2026-09-14T23:57:52.102788+00:00 · Updated: 2026-09-14T23:57:52.102788+00:00 · Edition: 2026-11-05
- Framing: model-written (headline, standfirst, why it matters, tags); source facts deterministic

## Briefing
- Puppeteer: Puppeteer released version 25.9.0 of puppeteer-core, updating browser versions and adding support for shadow roots in MutationPoller and tool execution cancellation in webmcp.

## Why it matters
This is a routine maintenance release that keeps Puppeteer aligned with the latest Firefox and Chrome builds, ensuring compatibility for users relying on the library for browser automation. The addition of shadow root support in MutationPoller is a minor but useful improvement for scraping or testing within Shadow DOM, while the webmcp cancellation feature offers better control for agent-based workflows.

## Sources
- Primary source · Puppeteer · 2026-08-25 — [puppeteer/puppeteer puppeteer-core: v25.9.0](https://github.com/puppeteer/puppeteer/releases/tag/puppeteer-core-v25.9.0)

## Watch next
Will Puppeteer add further Shadow DOM enhancements or expand webmcp capabilities in upcoming releases?

Topics: Puppeteer, Firefox, Chrome, puppeteer, browser-automation, release, firefox, chrome, shadow-dom, webmcp

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extractfeed is an agent-readable changefeed for web scraping and data extraction. Index: https://extractfeed.io/agents.md