vulnerability
Ubuntu: (Multiple Advisories) (CVE-2021-38503): Firefox vulnerabilities
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:P/I:P/A:P) | Nov 3, 2021 | Nov 4, 2021 | Mar 27, 2026 |
Severity
8
CVSS
(AV:N/AC:L/Au:N/C:P/I:P/A:P)
Published
Nov 3, 2021
Added
Nov 4, 2021
Modified
Mar 27, 2026
Description
The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
Solutions
ubuntu-upgrade-firefoxubuntu-upgrade-thunderbird
References
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.