---
id: CVE-2025-4085
title: >-
  An attacker with control over a content process could potentially leverage the
  privileged UITour actor to leak sensitive information or escalate privileges
summary: >-
  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.
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N'
cwe:
  - CWE-269
vendor: mozilla
product: firefox
affected:
  - firefox < 138.0
  - thunderbird < 138.0
patched:
  - firefox 138.0
  - thunderbird 138.0
published: '2025-04-29'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T18:10:00.190'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-4085'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1915280'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-28/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-31/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.003
epssPercentile: 0.20512
ingestedAt: '2026-09-30T18:17:24.434Z'
---

## Overview

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.

## Affected

- `firefox < 138.0`
- `thunderbird < 138.0`

## Remediation

Upgrade past the affected range:

- `firefox 138.0`
- `thunderbird 138.0`