CVE-2021-29963: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Address bar search suggestions in private browsing mode were re-using session data from normal mode. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 89.

Affected products

• Mozilla Firefox: before 89.0 (fixed in 89.0)

Published 2021-06-24. Last modified 2026-06-17.