CVEvulnerability

CVE-2025-5986

6.5 MEDIUM Published 2025-06-11 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2025-06-11
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weaknesses
CWE-451

Description

A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability was fixed in Thunderbird 128.11.1 and Thunderbird 139.0.2.

Affected configurations

• mozilla thunderbird (< 128.11.1) • mozilla thunderbird (>= 135.0 < 139.0.2)

Related

Weakness · CWE (1)

  • CWE-451 User Interface (UI) Misrepresentation of Critical Information weakness

References