VDB
CVE-2026-74956
CVE-2026-74956
PUBLISHED
CVSS 9.1 CRITICAL
Reported by mozilla · Published August 18, 2026
Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Risk Scores
CVSS 3.1
9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | 153.1, 154 |
| Mozilla | Thunderbird | 153.1, 154 |
| Mozilla | Thunderbird | 153.1, 154 |
| Mozilla | Firefox | 154, 153.1 |
| wolfi | firefox | 0, 0, 0 |
| chainguard | firefox | 0, 0, 0 |
Timeline
- Aug 18, 2026 Coalition ESS Score
- Aug 18, 2026 CVE Published
- Aug 18, 2026 CVE Updated
- Aug 24, 2026 EPSS Score
- Aug 28, 2026 EPSS Score
- Sep 4, 2026 EPSS Score
- Sep 5, 2026 Security Advisory
- Sep 9, 2026 EPSS Score
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score
- Sep 18, 2026 EPSS Score
- Sep 24, 2026 EPSS Score