CVE-2026-2799 is a use-after-free vulnerability identified in the DOM: Core & HTML component of Mozilla Firefox. Use-after-free issues occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to arbitrary code execution or application crashes. This vulnerability was addressed and fixed in Firefox 148. The CVSS v3.1 base score is 8.8, indicating high impact with network attack vector, low attack complexity, no privileges required, user interaction required, and high confidentiality, integrity, and availability impacts. The vendor advisory from Mozilla confirms the fix and provides detailed references to the bug tracking the issue.

Successful exploitation of this use-after-free vulnerability could lead to arbitrary code execution, information disclosure, or denial of service in affected Firefox versions prior to 148. The vulnerability is rated high severity with a CVSS score of 8.8, reflecting significant potential impact on confidentiality, integrity, and availability of the affected system.

Mozilla has released an official fix for this vulnerability in Firefox version 148. Users and administrators should update affected Firefox installations to version 148 or later to remediate this issue. No additional mitigation steps are required beyond applying the official update.