CVE-2025-5270

SNI was sometimes unencrypted

CVSS 7.5 HIGHEPSS 0.2%CWE-319

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.5EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

27 May 2025Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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/