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 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.
CVE-2026-110247
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-110247
Thunderbird
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Mozilla",
"product": "Thunderbird",
"versions": [
{
"status": "unaffected",
"version": "158",
"versionType": "rpm",
"lessThanOrEqual": "*"
}
]
}
]- Related CVEs
- CVE-2026-110247
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #49303 · Revision 1
- Added to Heist Feed
- Publisher date