Vulnerability Description
JIT miscompilation in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
CVSS Score
5.4
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.37.0 |
| Mozilla | Thunderbird | < 152.0.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2043139Permissions 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
FAQ
What is CVE-2026-12299?
CVE-2026-12299 is a vulnerability with a CVSS score of 5.4 (MEDIUM). JIT miscompilation in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
How severe is CVE-2026-12299?
CVE-2026-12299 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-12299?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.