CVE-2026-12296
published 2026-06-16CVE-2026-12296: Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird…
PriorityP348critical9.6CVSS 3.1
AVNACLPRNUIRSCCHIHAH
EPSS
0.39%
31.4th percentile
Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 152 | Firefox 152 |
| mozilla | firefox | < 140.12.0 | 140.12.0 |
| mozilla | firefox | < 152.0.0 | 152.0.0 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < Firefox ESR 140.12 | Firefox ESR 140.12 |
| mozilla | thunderbird | < Thunderbird 152 | Thunderbird 152 |
| mozilla | thunderbird | < Thunderbird 140.12 | Thunderbird 140.12 |
| mozilla | thunderbird | < 140.12.0 | 140.12.0 |
| mozilla | thunderbird | < 152.0.0 | 152.0.0 |
| mozilla | thunderbird | — | — |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.19.6CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
vendor_redhat7.5HIGH
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Red Hat
firefox: thunderbird: Sandbox escape in the Security: Process Sandboxing component
vendor_redhat·2026-06-16·CVSS 7.5
CVE-2026-12296 [HIGH] CWE-403 firefox: thunderbird: Sandbox escape in the Security: Process Sandboxing component
firefox: thunderbird: Sandbox escape in the Security: Process Sandboxing component
Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape in the Security: Process Sandboxing 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) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red H
Mozilla
Mozilla Foundation Security Advisory 2026-57: CVE-2026-12296
vendor_mozilla
CVE-2026-12296 Mozilla Foundation Security Advisory 2026-57: CVE-2026-12296
Mozilla Foundation Security Advisory 2026-57
CVE: CVE-2026-12296
Product: Firefox
Impact: high
Fixed in: Firefox 152
Mozilla
Mozilla Foundation Security Advisory 2026-58: CVE-2026-12296
vendor_mozilla
CVE-2026-12296 Mozilla Foundation Security Advisory 2026-58: CVE-2026-12296
Mozilla Foundation Security Advisory 2026-58
CVE: CVE-2026-12296
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.12
Mozilla
Mozilla Foundation Security Advisory 2026-60: CVE-2026-12296
vendor_mozilla
CVE-2026-12296 Mozilla Foundation Security Advisory 2026-60: CVE-2026-12296
Mozilla Foundation Security Advisory 2026-60
CVE: CVE-2026-12296
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 152
Mozilla
Mozilla Foundation Security Advisory 2026-61: CVE-2026-12296
vendor_mozilla
CVE-2026-12296 Mozilla Foundation Security Advisory 2026-61: CVE-2026-12296
Mozilla Foundation Security Advisory 2026-61
CVE: CVE-2026-12296
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.12
VulDB
Mozilla Firefox up to 151 Process Sandboxing sandbox (Nessus ID 321490 / WID-SEC-2026-1959)
vuldb·2026-07-03·CVSS 9.6
CVE-2026-12296 [CRITICAL] Mozilla Firefox up to 151 Process Sandboxing sandbox (Nessus ID 321490 / WID-SEC-2026-1959)
A vulnerability was found in Mozilla Firefox up to 151. It has been classified as critical. Impacted is an unknown function of the component Process Sandboxing. This manipulation causes sandbox issue.
The identification of this vulnerability is CVE-2026-12296. It is possible to initiate the attack remotely. There is no exploit available.
Upgrading the affected component is recommended.
GHSA
Sandbox escape in the Security: Process Sandboxing component.
ghsa_unreviewed·2026-06-16
CVE-2026-12296 Sandbox escape in the Security: Process Sandboxing component.
Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152 and Firefox ESR 140.12.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2040515https://www.mozilla.org/security/advisories/mfsa2026-57/https://www.mozilla.org/security/advisories/mfsa2026-58/https://www.mozilla.org/security/advisories/mfsa2026-60/https://www.mozilla.org/security/advisories/mfsa2026-61/https://access.redhat.com/errata/RHSA-2026:27717https://access.redhat.com/errata/RHSA-2026:27733https://access.redhat.com/errata/RHSA-2026:27734https://access.redhat.com/errata/RHSA-2026:29940https://access.redhat.com/errata/RHSA-2026:30846https://access.redhat.com/errata/RHSA-2026:33445https://access.redhat.com/errata/RHSA-2026:36100https://access.redhat.com/errata/RHSA-2026:36101https://access.redhat.com/errata/RHSA-2026:36102https://access.redhat.com/errata/RHSA-2026:36103https://access.redhat.com/errata/RHSA-2026:37210https://access.redhat.com/errata/RHSA-2026:37391https://access.redhat.com/errata/RHSA-2026:38506https://access.redhat.com/errata/RHSA-2026:38750https://access.redhat.com/errata/RHSA-2026:38751https://access.redhat.com/errata/RHSA-2026:38753https://access.redhat.com/security/cve/CVE-2026-12296https://bugzilla.redhat.com/show_bug.cgi?id=2489232https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12296.json
2026-06-16
Published