CVE-2026-100804
published 2026-09-29CVE-2026-100804: Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.
PriorityP346critical9.6CVSS 3.1
AVNACLPRNUIRSCCHIHAH
EPSS
0.30%
21.1th percentile
Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 157 | Firefox 157 |
| mozilla | thunderbird | < Thunderbird 157 | Thunderbird 157 |
CVSS provenance
nvdv3.19.6CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
vendor_redhat9.6CRITICAL
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Red Hat
firefox: Sandbox escape due to use-after-free in the Preferences: Backend component
vendor_redhat·2026-09-29·CVSS 9.6
CVE-2026-100804 [CRITICAL] CWE-825 firefox: Sandbox escape due to use-after-free in the Preferences: Backend component
firefox: Sandbox escape due to use-after-free in the Preferences: Backend component
Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape due to use-after-free in the Preferences: Backend 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: firefox (Red Hat Enterprise Linux 6) - Not affected
Package: firefox (Red Hat Enterprise Linux 7) - Not affected
P
Mozilla
Mozilla Foundation Security Advisory 2026-101: CVE-2026-100804
vendor_mozilla·CVSS 9.6
CVE-2026-100804 [CRITICAL] Mozilla Foundation Security Advisory 2026-101: CVE-2026-100804
Mozilla Foundation Security Advisory 2026-101
CVE: CVE-2026-100804
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 157
Mozilla
Mozilla Foundation Security Advisory 2026-97: CVE-2026-100804
vendor_mozilla·CVSS 9.6
CVE-2026-100804 [CRITICAL] Mozilla Foundation Security Advisory 2026-97: CVE-2026-100804
Mozilla Foundation Security Advisory 2026-97
CVE: CVE-2026-100804
Product: Firefox
Impact: low
Fixed in: Firefox 157
GHSA
Sandbox escape due to use-after-free in the Preferences: Backend component.
ghsa_unreviewed·2026-09-29
CVE-2026-100804 [CRITICAL] CWE-416 Sandbox escape due to use-after-free in the Preferences: Backend component.
Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Firefox 157.
No detection rules found.
No public exploits indexed.
2026-09-29
Published