CVE-2025-4083
firefox-esr - security update
9.1
CRITICAL
CVSS 3.1
EPSS 0.34%
Description
A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.
How to fix CVE-2025-4083
To remediate CVE-2025-4083, upgrade the affected package to a fixed version below.
- —upgrade to 128.10.1esr-1~deb11u1 or later
- —upgrade to 128.10.1esr-1~deb11u1 or later
- —upgrade to 128.10.0esr-1~deb12u1 or later
- —upgrade to 1:128.10.1esr-1~deb11u1 or later
Is CVE-2025-4083 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 128.10.1esr-1~deb11u1
- from 0, < 128.10.1esr-1~deb11u1
- from 0, < 128.10.0esr-1~deb12u1
- from 0, < 1:128.10.1esr-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |