CVE-2026-84640

A flaw was found in Thunderbird. A remote attacker could exploit this vulnerability by sending a maliciously constructed mail header. This could lead to a one-byte read past the end of a buffer, potentially resulting in information disclosure or other unpredictable behavior.

Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.