CyberRota Analysis
AI-GeneratedN-able Mail Assure has a design-level authorization flaw that allows authenticated SMTP users to send emails using MAIL FROM addresses belonging to other tenants, bypassing domain-to-account binding. This vulnerability enables attackers to impersonate other tenant domains, resulting in messages that successfully pass SPF and DMARC validation, potentially leading to phishing and spoofing attacks. Organizations utilizing N-able Mail Assure should prioritize addressing this issue to mitigate risks associated with unauthorized email impersonation.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD 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.