CVE-2026-110247
highSeveral buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks.
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.
CVSS
8.4
8.4 (CVSS v3.1)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
Timeline (UTC)
Published: 2026-10-13 19:18
Modified: 2026-10-27 19:17
NVD status: Awaiting Analysis
Last synced 19 hours ago
Verified against the source API 2026-10-28 11:30 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2071621 security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-109/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-122/ security@mozilla.org
Data sources
NVD CVE API 2.0 — fetched 2026-10-28 11:30 UTC · record ↗