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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-5986 Detail

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 affects Thunderbird < 128.11.1 and Thunderbird < 139.0.2.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1958580%2C1968012 Broken Link 
https://www.mozilla.org/security/advisories/mfsa2025-49/ Vendor Advisory 
https://www.mozilla.org/security/advisories/mfsa2025-50/ Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-451 User Interface (UI) Misrepresentation of Critical Information CISA-ADP  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-5986
NVD Published Date:
06/11/2025
NVD Last Modified:
07/02/2025
Source:
Mozilla Corporation