VulnerabilityModified
CVE-2026-12297
This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
CRITICAL 9.6EPSS 0.39%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
- CVSS 3.1
- 9.6 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- EPSS
- 0.39% probability · 33th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-119, CWE-653
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2041610Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-57/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-58/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-59/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-60/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-61/Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:27717
- https://access.redhat.com/errata/RHSA-2026:27733
- https://access.redhat.com/errata/RHSA-2026:27734
- https://access.redhat.com/errata/RHSA-2026:29940
- https://access.redhat.com/errata/RHSA-2026:30846
- https://access.redhat.com/errata/RHSA-2026:33445
- https://access.redhat.com/errata/RHSA-2026:36100
- https://access.redhat.com/errata/RHSA-2026:36101
- https://access.redhat.com/errata/RHSA-2026:36102
- https://access.redhat.com/errata/RHSA-2026:36103
- https://access.redhat.com/errata/RHSA-2026:37210
- https://access.redhat.com/errata/RHSA-2026:37391
- https://access.redhat.com/errata/RHSA-2026:38506
- https://access.redhat.com/errata/RHSA-2026:38750
- https://access.redhat.com/errata/RHSA-2026:38751
- https://access.redhat.com/errata/RHSA-2026:38753
- https://access.redhat.com/errata/RHSA-2026:39011
- https://access.redhat.com/errata/RHSA-2026:39141
- https://access.redhat.com/errata/RHSA-2026:39142
- https://access.redhat.com/errata/RHSA-2026:39428
- https://access.redhat.com/errata/RHSA-2026:39706
- https://access.redhat.com/security/cve/CVE-2026-12297
- https://bugzilla.redhat.com/show_bug.cgi?id=2489235
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12297.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.