Description

Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally. When an email is opened, Thunderbird accesses the specified URL to determine file size, and navigates to it when the user clicks the attachment. Because the URL is not validated or sanitized, it can reference internal resources like chrome:// or SMB share file:// links, potentially leading to hashed Windows credential leakage and opening the door to more serious security issues. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.

INFO

Published Date :

2025-04-15T15:06:13.599Z

Last Modified :

2026-04-13T14:28:27.731Z

Source :

mozilla
AFFECTED PRODUCTS

The following products are affected by CVE-2025-3522 vulnerability.

Vendors Products
Mozilla
  • Thunderbird
Redhat
  • Enterprise Linux
  • Rhel Aus
  • Rhel E4s
  • Rhel Eus
  • Rhel Tus
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-3522.

URL Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1955372 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-3522 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-3522 cve-icon
https://www.mozilla.org/security/advisories/mfsa2025-26/ cve-icon cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2025-27/ cve-icon cve-icon cve-icon
Login to claim this CVE

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact