Clickjacking in Firefox/Thunderbird widget component before v154
CVE-2026-74978 Published on August 18, 2026
Clickjacking issue in the Widget component
Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Vulnerability Analysis
CVE-2026-74978 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a Clickjacking Vulnerability?
The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with. A web application is expected to place restrictions on whether it is allowed to be rendered within frames, iframes, objects, embed or applet elements. Without the restrictions, users can be tricked into interacting with the application when they were not intending to.
CVE-2026-74978 has been classified to as a Clickjacking vulnerability or weakness.
Products Associated with CVE-2026-74978
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Affected Versions
Mozilla Firefox:- Version 153.1, <= 153.* is unaffected.
- Version 154, <= * is unaffected.
- Version 153.1, <= 153.* is unaffected.
- Version 154, <= * is unaffected.