SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-16398

This vulnerability was fixed in Firefox 153 and Thunderbird 153.

HIGH 7.5EPSS 0.15%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

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
0.15% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-200, CWE-346
Affected
mozilla/firefox · mozilla/thunderbird
Source
security@mozilla.org

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