SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-5270

This vulnerability was fixed in Firefox 139 and Thunderbird 139.

HIGH 7.5EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
0.29% probability · 21th percentile
CISA KEV
Not listed
Weakness
CWE-319
Affected
mozilla/firefox
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.