CVE-2022-31742: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

An attacker could have exploited a timing attack by sending a large number of allowCredential entries and detecting the difference between invalid key handles and cross-origin key handles. This could have led to cross-origin account linking in violation of WebAuthn goals. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

Affected products

• Mozilla Firefox: before 101 (fixed in 101)
• Mozilla Firefox ESR: before 91.10 (fixed in 91.10)
• Mozilla Thunderbird: before 91.10 (fixed in 91.10)

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