VDB
CVE-2026-74960
CVE-2026-74960
PUBLISHED
CVSS 8.1 HIGH
Reported by mozilla · Published August 18, 2026
Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Risk Scores
CVSS 3.1
8.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | 140.14, 153.1, 154 |
| Mozilla | Thunderbird | 140.14, 153.1, 154 |
| Mozilla | Thunderbird | 140.14, 153.1, 154 |
| Mozilla | Firefox | 140.14, 153.1, 154 |
Timeline
- Aug 18, 2026 Coalition ESS Score
- Aug 18, 2026 CVE Published
- Aug 18, 2026 CVE Updated
- Aug 24, 2026 EPSS Score
- Aug 24, 2026 Distribution Patch
- Aug 24, 2026 Security Advisory
- Aug 24, 2026 Distribution Patch
- Aug 24, 2026 Security Advisory
- Aug 25, 2026 EPSS Score
- Aug 25, 2026 Distribution Patch
- Aug 25, 2026 Security Advisory
- Sep 3, 2026 Distribution Patch