CVE-2026-86060

critical

Description

RouterOS contains an argument-handling flaw in the SSH login path involving usernames that begin with a prohibited character, allowing for the trusted RouterOS policy mask to be changed, leading to privilege escalation. Exploitation requires an unauthenticated SSH session to reach the RouterOS login helper.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)

References

https://mikrotik.com/supportsec/september-2026-vulnerability/

https://www.malwarebytes.com/blog/news/2026/09/mikrotik-routers-can-be-taken-over-without-password

https://www.helpnetsecurity.com/2026/09/07/mikrotik-routeros-ssh-vulnerabilities-exploited/

https://www.databreachtoday.com/mikrotik-issues-patches-for-routers-amid-zero-day-attacks-a-32762

https://www.bleepingcomputer.com/news/security/hackers-exploit-new-mikrotik-routeros-flaws-to-hijack-routers/

https://securityaffairs.com/198538/security/your-mikrotik-router-may-already-be-compromised-look-for-ssh-user-2.html

https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/

https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800

https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801

https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802

https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/

https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve

Details

Source: Mitre, NVD

Published: 2026-09-05

Updated: 2026-09-09

Named Vulnerability: MikroTrick

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.2

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.00401