CVE-2019-3979: MikroTik RouterOS

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below are vulnerable to a DNS unrelated data attack. The router adds all A records to its DNS cache even when the records are unrelated to the domain that was queried. Therefore, a remote attacker controlled DNS server can poison the router's DNS cache via malicious responses with additional and untrue records.

Affected products

• MikroTik RouterOS: up to and including 6.44.5; up to and including 6.45.6

Published 2019-10-29. Last modified 2026-06-17.