A vulnerability, which was classified as critical, was found in Mozilla Thunderbird up to 128.10.0/138.0.0. Affected is an unknown function of the component Header Handler. The manipulation of the argument X-Mozilla-External-Attachment-URL leads to Remote Code Execution.
This vulnerability is traded as CVE-2025-3932. It is possible to launch the attack remotely. There is no exploit available.
It is recommended to upgrade the affected component.
