CVE-2026-16405
HIGHCVSS 7.5/10EPSS 0.26%
Last modified
CVE-2026-16405 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Information disclosure in the Networking: WebSockets component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.. EPSS estimates a 0.26% chance of exploitation in the next 30 days.
Description
Information disclosure in the Networking: WebSockets component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 153.0.0 |
| Mozilla | Firefox | >= 140.1.0, < 140.13.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2036591Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-70/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-16405?
Information disclosure in the Networking: WebSockets component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
How severe is CVE-2026-16405?
CVE-2026-16405 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.
How do I fix CVE-2026-16405?
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-2026-1640The Taskbuilder – WordPress Project Management & Task Manage…4.3
- CVE-2026-16400Information disclosure in the DOM: Security component. This …7.5
- CVE-2026-16401Privilege escalation in the Data Loss Prevention component. …8.8
- CVE-2026-16402Integer overflow in the Graphics: ImageLib component. This v…9.8
- CVE-2026-16403Spoofing issue in the Address Bar component. This vulnerabil…6.5
- CVE-2026-16404Spoofing issue in Firefox for Android. This vulnerability wa…7.4
- CVE-2026-16406Mitigation bypass in the Networking component. This vulnerab…9.1
- CVE-2026-16407Mitigation bypass in the DOM: Service Workers component. Thi…9.8
- CVE-2026-16408Integer overflow in the Audio/Video: Playback component. Thi…9.8
- CVE-2026-16409Invalid pointer in the Security: PSM component. This vulnera…7.5
- CVE-2026-16410JIT miscompilation in the JavaScript Engine: JIT component. …9.8
- CVE-2026-16411Memory safety bugs present in Firefox 152. Some of these bug…9.8
Are you affected by CVE-2026-16405?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST