CVE-2026-8401
Critical
Description
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.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Mozilla Firefox
PublishedMay 12, 2026
First seenMay 12, 2026
Weakness typeCWE-693CWE-693CWE-653CWE-653
How to fix
Update
- mozilla firefox150.0.3 or later
Vendor advisories
- access.redhat.com/errata/RHSA-2026:26551
- access.redhat.com/errata/RHSA-2026:27715
- access.redhat.com/errata/RHSA-2026:26539
- access.redhat.com/errata/RHSA-2026:21380
- access.redhat.com/errata/RHSA-2026:22325
- access.redhat.com/errata/RHSA-2026:21382
- access.redhat.com/errata/RHSA-2026:22643
- access.redhat.com/errata/RHSA-2026:26629
- access.redhat.com/errata/RHSA-2026:26270
- access.redhat.com/errata/RHSA-2026:26606
- access.redhat.com/errata/RHSA-2026:26536
- access.redhat.com/errata/RHSA-2026:26630
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 150.0.3 | 150.0.3 |
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