CVE-2025-5986 (GCVE-0-2025-5986)

Vulnerability from cvelistv5 – Published: 2025-06-11 12:07 – Updated: 2026-04-13 14:28
VLAI
Title
Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links
Summary
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.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-06-11 13:20 UTC
CWE
  • CWE-451 - User Interface (UI) Misrepresentation of Critical Information
Assigner
mozilla CNA under the mitre root
CNA scorecard E 38/100 over 683 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Mozilla Thunderbird Unaffected: 128.11.1 , ≤ 128.* (rpm)
Unaffected: 139.0.2 , ≤ * (rpm)
guessed Create a notification for this product.
Credits
Dario Weißer
Show details on NVD website
To clipboard 

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