Vulnerability Description
It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Thunderbird | < 128.10.1 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1960412Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2025-34/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-35/Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/05/msg00022.html
FAQ
What is CVE-2025-3932?
CVE-2025-3932 is a vulnerability with a CVSS score of 6.5 (MEDIUM). It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block re...
How severe is CVE-2025-3932?
CVE-2025-3932 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-3932?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Thunderbird.