[ CVE-2026-110247 · Published 13 Oct 2026 ]
Vulnerability in Mozilla Thunderbird
[ Description ]Official 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.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.
[ Advisories ]Government CERT advisories
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CERT-FRCERTFR-2026-AVI-1305
Multiple vulnerabilities in Mozilla products Translated from French
Multiple vulnerabilities have been discovered in Mozilla products. Some of them allow an attacker to cause privilege escalation, remote denial of service and a breach of data confidentiality.
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BSI CERT-BundWID-SEC-2026-3942
Mozilla Firefox and Thunderbrid: Multiple vulnerabilities Translated from German