CVE-2025-3932

Tracking Links in Attachments Bypassed Remote Content Blocking

Medium · published May 14, 2025

CVSS v3.1
6.5
EPSS
0%
Percentile
31.7
In the wild
Unconfirmed
What it is

It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00388 · 31.7th percentile
Published
2025-05-14T16:56Z
EPSS history
Timeline
  • 14 MAY 16:56Z
    Tracking Links in Attachments Bypassed Remote Content Blocking
    cvelistv5