Vulnerability Description
N-able Mail Assure through April 2026 contains a design-level authorization flaw that allows an authenticated SMTP user to send outbound email using MAIL FROM addresses belonging to other tenants. When connecting to the SMTP TCP port and performing SMTP AUTH with valid credentials, the server accepts arbitrary sender domains without enforcing any domain-to-account binding. As a result, an attacker from any tenant can impersonate other tenant domains, producing messages that pass SPF and DMARC validation. NOTE: N-able's position is that the behavior is intended functionality of its shared SMTP relay architecture and that the service does not represent that it enforces per-tenant sender-domain binding.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://deepsec.net/speaker.html#PSLOT782
- https://gist.github.com/alessandrobertoldi/1ebe0f48aa0119d787ac0ff710057d92
- https://www.n-able.com/products/mail-assure
- http://seclists.org/fulldisclosure/2026/Jun/10
- https://github.com/alessandrobertoldi/research/blob/main/infinity-day-at-scale-d
FAQ
What is CVE-2025-68624?
CVE-2025-68624 is a vulnerability with a CVSS score of 4.3 (MEDIUM). N-able Mail Assure through April 2026 contains a design-level authorization flaw that allows an authenticated SMTP user to send outbound email using MAIL FROM addresses belonging to other tenants. Whe...
How severe is CVE-2025-68624?
CVE-2025-68624 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-68624?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.