CVE-2026-8401
published 2026-05-12CVE-2026-8401: Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.
PriorityP349critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.31%
23.4th percentile
Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 150.0.3 | Firefox 150.0.3 |
| mozilla | firefox | < 150.0.3 | 150.0.3 |
| mozilla | firefox_esr | < Firefox ESR 140.11 | Firefox ESR 140.11 |
| mozilla | firefox_esr | < Firefox ESR 115.36 | Firefox ESR 115.36 |
| mozilla | thunderbird | < Thunderbird 140.11 | Thunderbird 140.11 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
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Red Hat
firefox: Sandbox escape in the Profile Backup component
vendor_redhat·2026-05-12·CVSS 9.8
CVE-2026-8401 [CRITICAL] CWE-653 firefox: Sandbox escape in the Profile Backup component
firefox: Sandbox escape in the Profile Backup component
Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape in the Profile Backup 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
Package: firefox (Red Hat Enterprise
Mozilla
Mozilla Foundation Security Advisory 2026-48: CVE-2026-8401
vendor_mozilla·CVSS 9.8
CVE-2026-8401 [CRITICAL] Mozilla Foundation Security Advisory 2026-48: CVE-2026-8401
Mozilla Foundation Security Advisory 2026-48
CVE: CVE-2026-8401
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-51: CVE-2026-8401
vendor_mozilla·CVSS 9.8
CVE-2026-8401 [CRITICAL] Mozilla Foundation Security Advisory 2026-51: CVE-2026-8401
Mozilla Foundation Security Advisory 2026-51
CVE: CVE-2026-8401
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-47: CVE-2026-8401
vendor_mozilla·CVSS 9.8
CVE-2026-8401 [CRITICAL] Mozilla Foundation Security Advisory 2026-47: CVE-2026-8401
Mozilla Foundation Security Advisory 2026-47
CVE: CVE-2026-8401
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.36
Mozilla
Mozilla Foundation Security Advisory 2026-45: CVE-2026-8401
vendor_mozilla
CVE-2026-8401 Mozilla Foundation Security Advisory 2026-45: CVE-2026-8401
Mozilla Foundation Security Advisory 2026-45
CVE: CVE-2026-8401
Product: Firefox
Impact: high
Fixed in: Firefox 150.0.3
VulDB
Mozilla Firefox up to 150.0.2 Profile Backup sandbox
vuldb·2026-05-19·CVSS 9.8
CVE-2026-8401 [CRITICAL] Mozilla Firefox up to 150.0.2 Profile Backup sandbox
A vulnerability was found in Mozilla Firefox up to 150.0.2 and classified as critical. This affects an unknown function of the component Profile Backup Component. Executing a manipulation can lead to sandbox issue.
This vulnerability is tracked as CVE-2026-8401. The attack can be launched remotely. No exploit exists.
It is suggested to upgrade the affected component.
GHSA
GHSA-rr5w-74h2-xqhc: Sandbox escape in the Profile Backup component
ghsa_unreviewed·2026-05-12
CVE-2026-8401 GHSA-rr5w-74h2-xqhc: Sandbox escape in the Profile Backup component
Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2038679https://www.mozilla.org/security/advisories/mfsa2026-45/https://www.mozilla.org/security/advisories/mfsa2026-47/https://www.mozilla.org/security/advisories/mfsa2026-48/https://www.mozilla.org/security/advisories/mfsa2026-51/https://access.redhat.com/errata/RHSA-2026:21378https://access.redhat.com/errata/RHSA-2026:21380https://access.redhat.com/errata/RHSA-2026:21381https://access.redhat.com/errata/RHSA-2026:21382https://access.redhat.com/errata/RHSA-2026:22325https://access.redhat.com/errata/RHSA-2026:22643https://access.redhat.com/errata/RHSA-2026:26174https://access.redhat.com/errata/RHSA-2026:26268https://access.redhat.com/errata/RHSA-2026:26269https://access.redhat.com/errata/RHSA-2026:26270https://access.redhat.com/errata/RHSA-2026:26491https://access.redhat.com/errata/RHSA-2026:26492https://access.redhat.com/errata/RHSA-2026:26493https://access.redhat.com/errata/RHSA-2026:26521https://access.redhat.com/errata/RHSA-2026:26536https://access.redhat.com/errata/RHSA-2026:26539https://access.redhat.com/errata/RHSA-2026:26551https://access.redhat.com/errata/RHSA-2026:26606https://access.redhat.com/errata/RHSA-2026:26629https://access.redhat.com/errata/RHSA-2026:26630https://access.redhat.com/errata/RHSA-2026:27715https://access.redhat.com/security/cve/CVE-2026-8401https://bugzilla.redhat.com/show_bug.cgi?id=2476492https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8401.json
2026-05-12
Published