CVE-2025-66514

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Prior to 5.5.3, a stored HTML injection in the Mail app's message list allowed an authenticated user to inject HTML into the email subjects. Javascript was correctly blocked by the content security policy of the Nextcloud Server code.

CVSS v3 3.5 LOW

3.5^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.1 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/nextcloud/mail/commit/c64fcc3b79e0c089b5e1d2e04a07bfa740b2ac09	Patch
https://github.com/nextcloud/mail/pull/11740	Issue Tracking Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-v394-8gpc-6fv5	Patch Vendor Advisory
https://hackerone.com/reports/3357036	Permissions Required Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nextcloud:mail:*:*:*:*:*:nextcloud:*:*

History

No history.

Information

Published : 2025-12-05 18:15

Updated : 2025-12-09 19:23

NVD link : CVE-2025-66514

Mitre link : CVE-2025-66514

CVE.ORG link : CVE-2025-66514

JSON object : View

Products Affected

nextcloud

mail

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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