CVE-2026-16399
HIGHCVSS 7.5/10EPSS 0.16%
Last modified
CVE-2026-16399 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.. EPSS estimates a 0.16% chance of exploitation in the next 30 days.
Description
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
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 | Thunderbird | < 153.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2049981Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-71/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-16399?
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
How severe is CVE-2026-16399?
CVE-2026-16399 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2026-16399?
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
- Same Subject, Wrong User: A Cross-Issuer Account Takeover in n8nStrix found an identity-binding bug in n8n's token-exchange flow enabling account takeover.
- 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-2026-16393Incorrect boundary conditions in the Graphics: WebGPU compon…9.1
- CVE-2026-16394Mitigation bypass in the DOM: Security component. This vulne…9.1
- CVE-2026-16395Integer overflow in the Audio/Video component. This vulnerab…9.8
- CVE-2026-16396Privilege escalation in WebExtensions. This vulnerability wa…8.8
- CVE-2026-16397Clickjacking issue in the WebExtensions component in Firefox…6.5
- CVE-2026-16398Site isolation issue in the Graphics component. This vulnera…7.5
- 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
Are you affected by CVE-2026-16399?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST