CVE-2026-4371 | BDVDB-2026-322159 Detail
MozillaThunderbird
Description#
A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact none, availability impact high. Attack vector: network.
Weaknesses#
References#
- https://bugzilla.mozilla.org/show_bug.cgi?id=2023493
- https://www.mozilla.org/security/advisories/mfsa2026-23/
- https://www.mozilla.org/security/advisories/mfsa2026-24/
- https://access.redhat.com/security/cve/CVE-2026-4371
- https://bugzilla.redhat.com/show_bug.cgi?id=2451001
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4371.json
- https://access.redhat.com/errata/RHSA-2026:8315
- https://access.redhat.com/errata/RHSA-2026:6342
- https://access.redhat.com/errata/RHSA-2026:6917
- https://access.redhat.com/errata/RHSA-2026:8285
- https://access.redhat.com/errata/RHSA-2026:8850
- https://access.redhat.com/errata/RHSA-2026:8289
- https://access.redhat.com/errata/RHSA-2026:8288
- https://access.redhat.com/errata/RHSA-2026:8286
- https://access.redhat.com/errata/RHSA-2026:8287
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.