CVE-2025-3523

User Interface (UI) Misrepresentation of attachment URL

Medium · published April 15, 2025

CVSS v3.1
6.4
EPSS
0%
Percentile
23.7
In the wild
Unconfirmed
What it is

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.

The record
Technical detail
CVSS v3.1
6.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00319 · 23.7th percentile
Published
2025-04-15T15:06Z
EPSS history
Timeline
  • 15 APR 15:06Z
    User Interface (UI) Misrepresentation of attachment URL
    cvelistv5