Rapid7’s 2026 Global Cybersecurity Summit is now available on-demand.Watch sessions.
Rapid7

vulnerability

Alpine Linux: CVE-2021-38506: Improper Restriction of Rendered UI Layers or Frames

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
Dec 8, 2021
Added
Aug 22, 2024
Modified
Jun 18, 2026

Description

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Solutions

alpine-linux-upgrade-firefox-esralpine-linux-upgrade-firefoxalpine-linux-upgrade-thunderbirdalpine-linux-upgrade-librewolf
Title
Rapid7 Labs

2026 Global Threat Landscape Report

The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.