CVE-2026-110247
HIGH
MEDIUM
Priority: 0.02
BB Relevance:
52/100
Published: 2026-10-13
Modified: 2026-10-27
First seen: 2026-10-29
Status: active
Attack Surface
Low Complexity
No Auth
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Local
AC:
Low
PR:
None
UI:
None
S:
Unchanged
C:
High
I:
High
A:
High
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.