Findings

CVE-2025-66514

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform.

Published Dec 5, 2025 · updated Oct 15, 2026 · nextcloud mail

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.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 5, 2025 · NIST NVD

    Detected

    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.

  2. Oct 15, 2026 · NIST NVD

    Updated

    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.

Affected

  • cpe nextcloud/mailversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2025-66514

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-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

    nvd.nist.gov

References

CVE-2025-66514 · ZeroDay Findings