Mozilla has released Firefox 142, the latest version of its web browser, featuring several new improvements, privacy enhancements, and security fixes. The update includes a replacement for the previously discontinued Pocket service, introduces new AI-driven features, and addresses multiple security vulnerabilities to enhance user protection.
The Pocket service was discontinued in July, and Firefox 142 replaces it with a curated news overview on the New Tab page. This new overview organizes news by topic, allowing users to customize their experience by selecting or deselecting specific topics of interest. This feature is currently being rolled out to users and may require some time to become universally available.
Firefox 142 introduces a link preview feature, accessible via the right-click context menu. This feature provides users with a preview of the content they can expect to find upon clicking a link. As an option, a locally implemented AI summarizes the content of the destination page, giving users a quick understanding of the link’s content before navigating to it. This “AI” functionality operates locally, preserving user privacy by processing data directly on the user’s machine.
Extended profile management, initially introduced in Firefox 138, receives further enhancements in Firefox 142. Users can now personalize their profiles using a selection of 28 icon options, expanded from the previous limit of six. Additionally, users have the option to upload and use their own custom icons for profile personalization. This feature allows users to visually distinguish between different Firefox profiles, enhancing organization and usability.
Since the introduction of vertical tabs in Firefox 136, browser add-ons have had the capability to place their icons in the sidebar. Firefox 142 gives users greater control over the appearance of the sidebar. Users can now right-click on these add-on icons to manage their visibility, allowing for a more streamlined and personalized browser interface. This feature addresses user feedback regarding the management of add-on icons within the Firefox interface.
Recognizing that strict tracking protection can sometimes lead to compatibility issues with specific websites, Firefox 142 introduces the ability to create exceptions for websites. This feature enables users to selectively disable tracking protection for websites where it interferes with functionality. Users must evaluate the importance of certain website functions when determining whether to create an exception, balancing privacy with usability.
Mozilla emphasizes its commitment to user privacy, differentiating itself from other major browser manufacturers through its privacy-centric approach. Unlike companies that collect user data for advertising purposes, Mozilla prioritizes user privacy. To that end, all AI features in Firefox are implemented locally, ensuring that user data is not transmitted to cloud services or external servers. This local processing design safeguards user information and prevents data collection by third parties.
Firefox 142 continues Mozilla’s commitment to discreet certificate validation through CRLite, a mechanism used since Firefox 137. CRLite efficiently verifies certificate revocation without disclosing user activity, not even to Mozilla itself. Firefox 142 disables the previous OCSP mechanism for domain certificates, which is also utilized by other browsers. According to Mozilla, CRLite offers improved data efficiency, increased speed, and a higher level of discretion compared to OCSP.
Mozilla Security Advisory 2025-64 details that Firefox 142 addresses at least nine identified vulnerabilities. Two externally reported vulnerabilities are categorized as high risk. One vulnerability (CVE-2025-9179) involves malicious code potentially breaking out of the browser sandbox through an invalid pointer in an audio/video component for DRM-protected content. The other (CVE-2025-9180) is a flaw in the Canvas2D graphics component that could be exploited to bypass the same-origin policy.
The Security Advisory also identifies three internally discovered vulnerabilities as high risk: CVE-2025-9184, CVE-2025-9185, and CVE-2025-9187. The specifics of these vulnerabilities remain unspecified in the documentation. The remaining vulnerabilities addressed in Firefox 142 are classified as medium or low risk, indicating a range of security improvements.
Mozilla intends to release Firefox 143 on September 16th, 2025.
