CVE-2026-12294
CRITICALCVSS 9.6/10EPSS 0.36%
Last modified
CVE-2026-12294 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. Sandbox escape in the DOM: Workers component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.. EPSS estimates a 0.36% chance of exploitation in the next 30 days.
Description
Sandbox escape in the DOM: Workers component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.37.0 |
| Mozilla | Firefox | < 152.0.0 |
| Mozilla | Firefox | >= 128.0, < 140.12.0 |
| Mozilla | Thunderbird | < 140.12.0 |
| Mozilla | Thunderbird | < 152.0.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2039873Permissions 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
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-12294?
Sandbox escape in the DOM: Workers 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-2026-12294?
CVE-2026-12294 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.
How do I fix CVE-2026-12294?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-12289Privilege escalation in the Graphics: WebRender component. T…8.8
- CVE-2026-1229The CombinedMult function in the CIRCL ecc/p384 package (sec…9.8
- CVE-2026-12290Memory safety bug fixed in Firefox 152. This vulnerability w…8.1
- CVE-2026-12291Use-after-free in the Networking: HTTP component. This vulne…8.8
- CVE-2026-12292Incorrect boundary conditions in the Web Audio component. Th…8.1
- CVE-2026-12293Use-after-free in the Graphics: WebGPU component. This vulne…9.8
- CVE-2026-12295Sandbox escape in the DOM: Navigation component. This vulner…9.6
- CVE-2026-12296Sandbox escape in the Security: Process Sandboxing component…9.6
- CVE-2026-12297Sandbox escape due to incorrect boundary conditions in the N…9.6
- CVE-2026-12298Memory safety bug fixed in Firefox 152. This vulnerability w…5.4
- CVE-2026-12299JIT miscompilation in the DOM: Core & HTML component. This v…5.4
- CVE-2026-1230GitLab has remediated an issue in GitLab CE/EE affecting all…6.5
Are you affected by CVE-2026-12294?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST