Vulnerability · NVD

CVE-2025-3522

CVE-2025-3522, medium severity (CVSS 6.3): 1 tracked app concerned, all fixed or indeterminable on their current version.

Severity (CVSS): 6.3
Exploitation: 0.3 %
Tracked apps: 1
Still exposed: 0

Published on 2025-04-15

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.

Attack vector : Network No privileges required

Show raw CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

EPSS 0.27% exploit very unlikely percentile 17.1%

Tracked apps referencing this CVE

For each app: the affected range, the fixing version, and where the tracked app stands today.

Mozilla Thunderbird Windows winget:Mozilla.Thunderbird

Affected <128.9.2 Fixed in 128.9.2 Latest tracked 156.0.1 patched

Observed affected builds (87)

115.14.0 115.13.0 115.12.2 115.12.1 115.11.1 115.11.0 115.10.2 115.10.1 115.10.0 115.9.0 115.8.1 115.8.0 115.7.0 115.6.1 115.6.0 115.5.2 115.5.1 115.4.2 115.4.1 115.3.3 115.3.2 115.3.1 115.3.0 115.2.3 115.2.2 115.0 102.15.0 102.14.0 102.13.0 102.12.0 +57 · see history

Vulnerable CPE configurations (2)

Vendor	Product	Platform	Versions	CPE 2.3 URI
mozilla	thunderbird All platforms (wildcard)	All platforms (wildcard)	<128.9.2	cpe:2.3:a:mozilla:thunderbird::::::::
mozilla	thunderbird All platforms (wildcard)	All platforms (wildcard)	≥129.0 <137.0.2	cpe:2.3:a:mozilla:thunderbird::::::::

View on NVD ↗ Advisory · www.mozilla.org

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