Firefox 151 Adds Anti Fingerprinting, Local Network Prompts

Firefox 151 packs big privacy upgrades into a small update, with Mozilla outlining several meaningful privacy and security improvements in version 151.0 released on 20 May 2026, including stronger anti-fingerprinting, broader protection for local network access, and more control over private sessions and permissions. One notable change is a new end private session control in Private Browsing Mode, featuring a fire-icon button that wipes the current private session’s data and starts a fresh one.

Under the hood, Firefox 151 tightens its defenses against browser fingerprinting in the default Standard Enhanced Tracking Protection mode, with Mozilla saying it reduces the number of uniquely identifiable users by about 14% overall and by roughly 49% on macOS. A further change rolling out to all users involves local network access restrictions, which now prompt for permission when websites or apps try to communicate with devices on the local network.

The update also quietly fixes several security vulnerabilities, including CVE‑2026‑8953, a sandbox escape due to a use-after-free in the Disability Access APIs component. Users running Firefox in home or small‑office environments are advised to update to benefit from fingerprinting protections, local network prompts, and security patches.