In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability was fixed in Firefox 139 and Thunderbird 139.
https://www.mozilla.org/security/advisories/mfsa2025-45/
https://www.mozilla.org/security/advisories/mfsa2025-42/
https://bugzilla.mozilla.org/show_bug.cgi?id=1910298
Source: Mitre, NVD
Published: 2025-05-27
Updated: 2026-04-13
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 0.00021