Critical MikroTik RouterOS Vulnerabilities Enable SSH Authentication Bypass and Privilege Escalation
Polish CERT disclosed three vulnerabilities in MikroTik routers, two of which have been actively exploited since at least September 2. The flaws, rated 9.2 on CVSS, affect devices with internet-facing SSH access and were discovered using OpenAI models GPT 5.5 Cyber and GPT 5.6 Sol followed by manual verification. CVE-2026-67276 allows authentication bypass when the attacker knows the username and public key module, while CVE-2026-86060 permits privilege escalation via usernames containing invalid characters. Their combination enables full device compromise. A third issue, CVE-2026-67277 rated 8.8, resides in the speed-test service and can cause denial of service. Patches are available in RouterOS versions 7.25beta3, 7.24.2, 7.23.4 and 6.49.21, and MikroTik added detection for prior compromise. Attacks began concurrently with patch release and leave distinctive log entries.
HabrSep 14, 2026Translated from Russian