CVE-2026-16398
published 2026-07-21CVE-2026-16398: Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
PriorityP339high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.15%
4.6th percentile
Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 153 | Firefox 153 |
| mozilla | firefox | < 153.0.0 | 153.0.0 |
| mozilla | thunderbird | < Thunderbird 153 | Thunderbird 153 |
| mozilla | thunderbird | < 153.0 | 153.0 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat7.5HIGH
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Red Hat
firefox: thunderbird: Site isolation issue in the Graphics component
vendor_redhat·2026-07-21·CVSS 7.5
CVE-2026-16398 [HIGH] CWE-653 firefox: thunderbird: Site isolation issue in the Graphics component
firefox: thunderbird: Site isolation issue in the Graphics component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Site isolation issue in the Graphics component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not affected
Package: firefox (Red Hat Enterprise Linux 6) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 6) - Not affected
Package: firefox
Mozilla
Mozilla Foundation Security Advisory 2026-71: CVE-2026-16398
vendor_mozilla
CVE-2026-16398 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16398
Mozilla Foundation Security Advisory 2026-71
CVE: CVE-2026-16398
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153
Mozilla
Mozilla Foundation Security Advisory 2026-68: CVE-2026-16398
vendor_mozilla
CVE-2026-16398 Mozilla Foundation Security Advisory 2026-68: CVE-2026-16398
Mozilla Foundation Security Advisory 2026-68
CVE: CVE-2026-16398
Product: Firefox
Impact: high
Fixed in: Firefox 153
GHSA
Site isolation issue in the Graphics component.
ghsa_unreviewed·2026-07-21
CVE-2026-16398 [HIGH] CWE-200 Site isolation issue in the Graphics component.
Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153.
No detection rules found.
No public exploits indexed.
2026-07-21
Published