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Status published
Low
CVE-2025-66514
Nextcloud Mail stored HTML injection in subject text
Vulnerability Description
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.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
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Credits & Attribution
No credits recorded in the NVD database.
References
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Affected Vendor
nextcloud
View all reports →Affected Software
security-advisories
Vulnerable Versions:
>= 5.2.0-beta.1, < 5.5.3
Timeline
Official Publish:
December 5th, 2025
Last Modified:
December 8th, 2025
Added to House:
July 22nd, 2026
CVSS Vectors
V3:
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N