PatchSiren cyber security CVE debrief
CVE-2026-12302 Mozilla CVE debrief
A mitigation bypass vulnerability was discovered in the DOM: Security component. This issue was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The vulnerability was publicly disclosed on [cvePublishedAt](https://www.cve.org/CVERecord?id=CVE-2026-12302).
- Vendor
- Mozilla
- Product
- Firefox
- CVSS
- MEDIUM 6.5
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-16
- Original CVE updated
- 2026-06-17
- Advisory published
- 2026-06-16
- Advisory updated
- 2026-06-17
Who should care
Users of Firefox, Firefox ESR
Technical summary
A mitigation bypass vulnerability was discovered in the DOM: Security component.
Defensive priority
High
Recommended defensive actions
- Update to Firefox 152, Firefox ESR 140.12, or Firefox ESR 115.37 or later.
Evidence notes
The CVE was published on [cvePublishedAt](https://www.cve.org/CVERecord?id=CVE-2026-12302).
Official resources
Public