CVE-2026-4371

Published Mar 24, 2026

Last updated a month ago

Overview

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.
Source
security@mozilla.org
NVD status
Modified
Products
thunderbird

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.4
Impact score
5.2
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Severity
HIGH

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-126

Social media

Hype score
Not currently trending

Configurations