Vulnerability in N-Able Mail Assure
CVE-2025-68624
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (27.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-68624?
- CVE-2025-68624 is a medium-severity vulnerability in N-Able Mail Assure, classified under Authentication Bypass by Spoofing. CVSS score: 4.3/10. Published 2026-09-14.
- How severe is CVE-2025-68624?
- Medium severity. CVSS v3 base score is 4.3 out of 10.