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MEDIUM · 6.4

CVE-2025-3523

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct li...

Vulnerability Description

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.

CVSS Score

6.4

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
LOW

Affected Products

VendorProductVersions
MozillaThunderbird< 128.9.2

Related Weaknesses (CWE)

CWE-451

References

FAQ

What is CVE-2025-3523?

CVE-2025-3523 is a vulnerability with a CVSS score of 6.4 (MEDIUM). When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct li...

How severe is CVE-2025-3523?

CVE-2025-3523 has been rated MEDIUM with a CVSS base score of 6.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-3523?

Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Thunderbird.