CVE-2026-74954

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 154 Firefox ESR versions prior to 153.1 Thunderbird versions prior to 154 Thunderbird versions prior to 153.1

Description Information disclosure occurs due to a side-channel in the Storage: Cache API component. A side-channel is a method of extracting information from a system by observing its physical or operational behavior rather than exploiting a direct software bug.

Recommendations Update Firefox to version 154. Update Firefox ESR to version 153.1. Update Thunderbird to version 154. Update Thunderbird to version 153.1.