CVE-2025-5270

SNI was sometimes unencrypted

CVSS 7.5 HIGHEPSS 0.2%CWE-319

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References

https://bugzilla.mozilla.org/show_bug.cgi?id=1910298 https://www.mozilla.org/security/advisories/mfsa2025-42/https://www.mozilla.org/security/advisories/mfsa2025-45/