CVE-2026-4711
CRITICALCVSS 9.8/10EPSS 0.40%
Last modified
CVE-2026-4711 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.. EPSS estimates a 0.40% chance of exploitation in the next 30 days.
Description
Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.9.0 |
| Mozilla | Firefox | < 149.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2017002Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-20/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-22/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-4711?
Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
How severe is CVE-2026-4711?
CVE-2026-4711 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.
How do I fix CVE-2026-4711?
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-2026-47102LiteLLM prior to 1.83.10 allows a user to modify their own u…8.8
- CVE-2026-47103Python StateMachine versions 3.0.0 before 3.2.0 contains a r…9.8
- CVE-2026-47104libusb before version 1.0.30 contains a one-byte out-of-boun…5.5
- CVE-2026-47105Rejected reason: This CVE ID has been rejected or withdrawn …
- CVE-2026-47106Ellucian Banner Self-Service before the April T2 release (20…5.4
- CVE-2026-47107Windmill prior to 1.703.2 contains an incorrect default perm…8.6
- CVE-2026-47110Tiptap for PHP before version 2.1.1 contains an input valida…7.1
- CVE-2026-47114IINA before 1.4.3 contains a user-assisted command execution…8.8
- CVE-2026-47117OpenMed before 1.5.2 contains a remote code execution vulner…9.8
- CVE-2026-47118Agent Zero before version 1.15 contains a path traversal vul…7.1
- CVE-2026-47119Agent Zero before version 1.15 contains a stored cross-site …6.1
- CVE-2026-4712Information disclosure in the Widget: Cocoa component. This …7.5
Are you affected by CVE-2026-4711?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST