SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-4085

An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges.

HIGH 7.1EPSS 0.30%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVSS 3.1
7.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
EPSS
0.30% probability · 23th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-269
Affected
mozilla/firefox · mozilla/thunderbird
Source
security@mozilla.org
EPSS trend
0%3%5%26 October 2026: 0.30%26 October 202626 October 2026

EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.