CVE-2025-3523 | Mozilla Thunderbird up to 128.9.1/137.0.1 Header X-Mozilla-External-Attachment-URL ui layer
A vulnerability has been found in Mozilla Thunderbird up to 128.9.1/137.0.1 and classified as problematic. This vulnerability affects unknown code of the component Header Handler. The manipulation of the argument X-Mozilla-External-Attachment-URL leads to improper restriction of rendered ui layers.
This vulnerability was named CVE-2025-3523. The attack can be initiated remotely. There is no exploit available.
It is recommended to upgrade the affected component.