CVE-2026-16377

CriticalCVSS 9.8/10Last modified Oct 24, 2026

Description

Mitigation bypass in the PDF Viewer 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-693

Affected software

No affected versions have been published.

Timeline

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

Related CVEs from 2026

CVE-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 ThundeCVE-2026-163879.8Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and ThunCVE-2026-163889.8Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVE-2026-16377: Critical severity, CVSS 9.8 | Vulnix