Firefox 151: Enhanced Privacy, VPN Locations, and Critical Security Fixes

Firefox 151 brings a wealth of updates to boost your online privacy, including refined VPN options, smarter tracking protection, and one-click private session cleanups. The update also patches over 30 security flaws and introduces handy tools like PDF merging and a refreshed New Tab page. Here’s everything you need to know in a Q&A format.

What privacy improvements does Firefox 151 offer?

Firefox 151 significantly strengthens your privacy defenses. For private browsing, you can now clear an entire session with a single click — no need to close the window — and start fresh with no history. Mozilla also improved tracking protection: advanced fingerprinting defenses now reduce the number of users advertisers can identify by 14% overall, and up to 50% on macOS. These measures make it harder for trackers to create a unique profile of your browsing habits, giving you greater anonymity online. The update also integrates these privacy features seamlessly, so you get robust protection without extra effort.

Source: www.pcworld.com

How does the VPN feature change in Firefox 151?

The free VPN introduced in Firefox 149 now offers a choice of virtual locations. You can pick from servers in the US, Canada, the UK, France, and Germany — the same countries where the VPN is currently available. To use it, you’ll need a free Mozilla account, which grants you 50 GB of VPN traffic per month. The location selection is rolling out gradually, so not all users may see it immediately. This update gives you more control over your online presence, allowing you to appear as if you’re browsing from another region — ideal for accessing geo‑restricted content or adding an extra layer of privacy.

What new PDF features are included?

The built‑in PDF viewer/editor in Firefox 151 gains the ability to merge multiple PDF files into a single document. This is a practical tool for combining separate PDFs — like scanning receipts or merging chapters — without needing third‑party software. The feature integrates directly into the existing PDF editor, so you can rearrange pages and then merge them seamlessly. Whether you’re a student compiling research or a professional unifying reports, this tool simplifies document management right within your browser.

What’s updated on the New Tab page?

The New Tab page in Firefox 151 gets a visual refresh with more background images to choose from, making your start page feel more personal. Mozilla also revamped the underlying infrastructure to prepare for upcoming features planned for Firefox 152, due June 16th. This means you can expect smoother updates and new interactive elements in the near future. For now, you can enjoy a cleaner, more customizable landing page that showcases your favorite sites and recommended content — all while maintaining your privacy preferences.

Firefox 151: Enhanced Privacy, VPN Locations, and Critical Security Fixes — Source: www.pcworld.com

How many security vulnerabilities does Firefox 151 fix?

Mozilla’s Security Advisory 2026-46 lists over 30 fixed security vulnerabilities. Of these, 28 were reported by external researchers. Mozilla classifies four as high risk, including a potential browser sandbox escape (CVE-2026-8945) — a critical issue that could allow an attacker to break out of the browser’s restricted environment. Eleven vulnerabilities are rated medium risk, and the rest are low risk. Additionally, three internally discovered bugs related to memory management were fixed. These patches ensure that Firefox 151 is significantly more secure than previous versions, protecting you from a range of exploits.

What other enhancements does Firefox 151 bring?

Beyond privacy and security, Firefox 151 adds several quality‑of‑life improvements. The internal translation page (about:translations) is now easily accessible from the “More Tools” menu, letting you translate web pages without sending data to external servers. Linux users can back up their Firefox profile locally and restore it across platforms — useful for switching devices or after a clean install. For corporate users, the update also includes ESR versions (140.11.0 and 115.36.0) with the same security fixes, though the latter is limited to older operating systems like Windows 7/8.1 and macOS 10.12–10.14.

How does one‑click private session cleanup work?

In private browsing windows, Firefox 151 introduces a single button that clears your entire session. Previously, you had to close the private window to erase your history. Now, clicking this button instantly wipes all active tabs’ browsing data — cookies, cache, history, and more — and opens a fresh private window. This is perfect for shared computers or when you want to quickly start a new search without traces of your previous activity. The feature is designed to be intuitive: the button appears within the private window’s toolbar, making it easy to find and use.