CVE-2026-74989
Mozilla Firefox, Thunderbird, firefox
Internally found bugs present in Thunderbird 153. 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 154 and Thunderbird 154.
- CVSS
- 9.8
- EPSS
- - - percentile
- CISA KEV
- Not listed
- Published
- 2026.08.18