CVE-2025-1014 is a vulnerability in Firefox and Thunderbird where certificate length was not properly checked when added to a certificate store. The issue is rated with low impact because in practice only trusted data was processed. This vulnerability affects Firefox versions prior to 135, Firefox ESR versions prior to 128.7, Thunderbird versions prior to 128.7, and Thunderbird versions prior to 135. Mozilla has fixed this issue in Firefox 135 and Thunderbird 135, as well as Firefox ESR 128.7 and Thunderbird 128.7.