CVE-2026-15719
firefox: thunderbird: Site isolation issue in the DOM: Navigation component
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 14, 2026
Updated · August 13, 2026
Description
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue: We are aware that exploit code for this is public however we are not aware of any attacks in the wild abusing this flaw.
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE-501 · Trust Boundary Violation