CVE Alert: CVE-2025-5986
Vulnerability Summary: CVE-2025-5986
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.
Affected Endpoints:
No affected endpoints listed.
Published Date:
6/11/2025, 12:15:29 PM
⚠️ CVSS Score:
Exploit Status:
Not ExploitedReferences:
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1958580%2C1968012
- https://www.mozilla.org/security/advisories/mfsa2025-49/
- https://www.mozilla.org/security/advisories/mfsa2025-50/
Recommended Action:
No proposed action available. Please refer to vendor documentation for updates.
A considerable amount of time and effort goes into maintaining this website, creating backend automation and creating new features and content for you to make actionable intelligence decisions. Everyone that supports the site helps enable new functionality.
If you like the site, please support us on “Patreon” or “Buy Me A Coffee” using the buttons below
To keep up to date follow us on the below channels.
