Site Isolation Vulnerability in Firefox Browser by Mozilla

CVE-2026-100821

What is CVE-2026-100821?

A site isolation vulnerability in the Panning and Zooming component of Mozilla's Firefox browser could potentially allow attackers to bypass security measures and access sensitive data across different sites. This issue was identified and subsequently resolved in Firefox versions 153.4, 157, 115.42, and 140.17. Users are advised to update to the latest versions to ensure complete protection against potential exploitation of this issue.

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