8.4
High
CVE-2026-110247 Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks
Description
Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks. On a sufficiently large message the growth guard could fail open, or the buffer could be reallocated smaller than required, and a subsequent memcpy would then write attacker-controlled data across adjacent heap allocations. This vulnerability was fixed in Thunderbird 158 and Thunderbird 153.6.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Thunderbird 158 | earliest → < 158 | 158 |
| Thunderbird 153.6 | earliest → < 153.6 | 153.6 |
References
- bugzilla.mozilla.org bugzilla.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
Timeline
- Published
- Last modified
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