CVE-2026-110247 — Integer overflow in libmime buffer growth could lead to heap corruption
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 th…
Published: 2026-10-13 · CVSS: 8.4 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7