9.8
Critical
CVE-2026-84142 Internally found bugs present in Thunderbird 154
Description
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 155 | earliest → < 155 | 155 |
| Thunderbird 155 | earliest → < 155 | 155 |
References
- Moderate Severity internally found bugs fixed in Thunderbird 155 bugzilla.mozilla.org
- Low Severity internally found bugs fixed in Thunderbird 155 bugzilla.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
Timeline
- Published
- Last modified
Other CVEs of Firefox
The 2221 CVEs of Firefox →
CVE-2026-120572
Incorrect boundary conditions in the Layout: Block and Inline component
8.8
High
CVE-2026-118027
Frame poisoning in the Layout component
9.1
Critical
CVE-2026-118024
Use-after-free in the Graphics: Text component
8.8
High
CVE-2026-118026
Invalid pointer in the JavaScript: GC component
8.8
High