VDB
CVE-2026-84142
CVE-2026-84142
PUBLISHED
CVSS 9.8 CRITICAL
Reported by mozilla · Published September 1, 2026
Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
Risk Scores
CVSS 3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | 155 |
| Mozilla | Thunderbird | 155 |
| chainguard | firefox | 0, 0 |
| wolfi | firefox | 0, 0, 0 |
| Mozilla | Thunderbird | 155, 155 |
| Mozilla | Firefox | 155, 155 |
Timeline
- Sep 1, 2026 Coalition ESS Score
- Sep 1, 2026 CVE Published
- Sep 2, 2026 EPSS Score
- Sep 3, 2026 CVE Updated
- Sep 4, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score
- Sep 18, 2026 EPSS Score