CVE-2026-16375

CriticalCVSS 9.8/10Last modified Oct 24, 2026

Description

Site isolation issue in the Networking: HTTP component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-346

Affected software

VendorProductVersions
MozillaFirefox—
MozillaThunderbird—

References

Timeline

Published
Jul 21, 2026
Last modified
Oct 24, 2026
NVD status
Analyzed

Related CVEs from 2026

CVE-2026-163767.5Denial-of-service in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.CVE-2026-163779.8Mitigation bypass in the PDF Viewer component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and ThunderCVE-2026-163787.5Other issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.CVE-2026-163798.8Privilege escalation in the DOM: Content Processes component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 1CVE-2026-16388.8A security flaw has been discovered in Tenda AC21 1.1.1.1/1.dmzip/16.03.08.16. The impacted element is the function mDMZSetCfg of the file /CVE-2026-163809.1Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.CVE-2026-163819.1Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153CVE-2026-163829.8Mitigation bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.CVE-2026-163839.8Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and ThCVE-2026-163847.5Information disclosure due to uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 153 and ThundeCVE-2026-163857.5Information disclosure due to uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 153 and ThundeCVE-2026-163867.5Information disclosure due to uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 153 and Thunde
CVE-2026-16375: Critical severity, CVSS 9.8 | Vulnix