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Mozilla has introduced significant enhancements to its anti-fingerprinting technology in Firefox 145, initially available in Private Browsing Mode and Enhanced Tracking Protection's Strict setting. The new measures, described as 'Phase 2' protections, further restrict websites' ability to collect unique device and browser characteristics, such as local fonts, hardware details, processor core counts, touch capabilities, and dock or taskbar dimensions. These updates build on previous efforts that had already reduced user trackability, with Mozilla now estimating that only about 20% of users can be uniquely fingerprinted under the new system. The protections also standardize certain outputs, like always reporting two CPU cores and reducing available screen height, to further limit the effectiveness of fingerprinting techniques.
Mozilla cautions that completely eliminating all fingerprinting signals could disrupt legitimate website functionality, so users retain the option to disable these protections on specific pages if necessary. The company plans to make these privacy features the default for all users after further testing and optimization. These updates reflect Mozilla's ongoing commitment to user privacy and its proactive approach to countering increasingly sophisticated online tracking methods.
See the reporting duties and controls this puts on the clock.
1 event from the most recent confirmed update back to the earliest known activity.
Mozilla released a Firefox update introducing new protections intended to reduce websites' ability to digitally fingerprint users. The update was reported as a security and privacy hardening measure aimed at limiting tracking through browser characteristics.
See what this changes for your reporting obligations and which controls it puts on the clock.
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Mozilla patched multiple Firefox vulnerabilities, including a privacy flaw that let websites create hidden, stable identifiers without cookies by abusing the order of entries returned by `IndexedDB`. Researchers Dai Nguyen and Martin Bajanik of Fingerprint reported that the issue could persist across sessions and defeat protections expected from Firefox Private Browsing mode and Tor Browser’s **New Identity** feature, allowing sites to correlate activity that users believed was isolated. Mozilla addressed the issue under **Bug 2024220** in **Firefox 150** and **Firefox ESR 140.10.0**, with additional fixes included in **Firefox 150.0.3** and documented in Mozilla security advisories **MFSA-2026-32** and **MFSA-2026-45**. The Tor Project also incorporated the fix in **Tor Browser 15.0.10**, while Germany’s dCERT later published **Advisory 2026-1477** covering multiple Mozilla Firefox vulnerabilities.
Jun 29, 2026
Mozilla is preparing to ship new **AI privacy controls** in *Firefox 148*, including a dedicated settings section and a **global “kill switch”** (`Block AI enhancements`) intended to disable all current and future browser AI features at once. The change is positioned as a way to reduce unwanted AI prompts and to prevent AI-related data sharing via external processing/API calls; the controls are being tested in *Firefox Nightly* with feedback solicited via Mozilla’s community channels. Separately, academic researchers reported that Google Chrome’s **Manifest v3 (MV3)** extension architecture does not materially degrade ad-blocking and anti-tracking effectiveness compared with **Manifest v2 (MV2)**, based on a study published in *Proceedings on Privacy Enhancing Technologies (PoPETs)*. The work evaluates the practical impact of MV3’s shift away from the blocking (synchronous) `chrome.webRequest` API toward the more constrained `chrome.declarativeNetRequest` model, concluding there was **no statistically significant reduction** in blocking performance and, in some cases, slight improvements in tracker blocking.
Jun 29, 2026
Mozilla released **Firefox 152.0.2** to patch multiple security issues, including a vulnerability in **MP4 processing** and several browser weaknesses affecting file handling, URL processing, and privacy protections. The update also addresses issues tied to the `file:` URL scheme and hardens browser behavior around sensitive interactions that could affect local resource access. Mozilla said the release includes additional protections relevant to web applications such as **Proton Drive**, along with interface and permission-handling changes that restrict features like screen color picking and the eyedropper tool. The company also indicated that a related `file:` URL fix is planned for **Firefox 153**, suggesting further tightening of local-file security controls in the next release.
Jul 12, 2026