CVE-2026-74955

HighCVSS 8.8/10Last modified Aug 21, 2026

Description

Privilege escalation in the Request Handling component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

Metrics

CVSS 3.1 8.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-269

Affected software

No affected versions have been published.

Timeline

Published
Aug 18, 2026
Last modified
Aug 21, 2026
NVD status
Analyzed

Related CVEs from 2026

CVE-2026-749569.1Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, ThunderbirdCVE-2026-749578.1Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, ThundeCVE-2026-749587.5Information disclosure in the WebRTC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and ThunderCVE-2026-749599.1Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, TCVE-2026-749608.1Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, ThuCVE-2026-749619.1Side-channel in the Web Audio component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 15CVE-2026-749628.1Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.CVE-2026-749635.4Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESRCVE-2026-749649.8Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird CVE-2026-749658.8Privilege escalation in the Shell Integration component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1,CVE-2026-749667.5Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and CVE-2026-749675.4Same-origin policy bypass in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox E
CVE-2026-74955: High severity, CVSS 8.8 | Vulnix