CVE-2025-5263
firefox-esr - security update
4.3
MEDIUM
CVSS 3.1
EPSS 0.18%
Description
Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
How to fix CVE-2025-5263
To remediate CVE-2025-5263, upgrade the affected package to a fixed version below.
- —upgrade to 128.11.0esr-1~deb11u1 or later
- —upgrade to 128.11.0esr-1~deb11u1 or later
- —upgrade to 128.11.0esr-1~deb12u1 or later
- —upgrade to 1:128.11.0esr-1~deb11u1 or later
Is CVE-2025-5263 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 128.11.0esr-1~deb11u1
- from 0, < 128.11.0esr-1~deb11u1
- from 0, < 128.11.0esr-1~deb12u1
- from 0, < 1:128.11.0esr-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |