CVE-2022-45403: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Service Workers should not be able to infer information about opaque cross-origin responses; but timing information for cross-origin media combined with Range requests might have allowed them to determine the presence or length of a media file. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.

Affected products

• Mozilla Firefox: before 107.0 (fixed in 107.0)
• Mozilla Firefox ESR: before 102.5 (fixed in 102.5)
• Mozilla Thunderbird: before 102.5 (fixed in 102.5)

Published 2022-12-22. Last modified 2026-06-17.