vulnerability
Debian: CVE-2025-5266: firefox-esr, thunderbird -- security update
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 4 | (AV:N/AC:M/Au:N/C:P/I:N/A:N) | May 27, 2025 | May 29, 2025 | Apr 15, 2026 |
Severity
4
CVSS
(AV:N/AC:M/Au:N/C:P/I:N/A:N)
Published
May 27, 2025
Added
May 29, 2025
Modified
Apr 15, 2026
Description
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Solutions
debian-upgrade-firefox-esrdebian-upgrade-thunderbird
Rapid7 Labs
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.