CVE-2026-67279

medium

Description

RouterOS SSH enters the connection protocol after a client-requested rekey even though user authentication was never attempted, allowing an unauthenticated client to open a session channel and send an exec request. On affected builds the server dispatches the command, enabling unauthenticated creation, overwrite, and reconstruction of files in the RouterOS managed file namespace, including support files containing configuration and diagnostic data.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://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/

https://www.securityweek.com/mikrotik-patches-critical-flaws-chained-to-hack-routers/

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: 2026-09-08

Risk Information

CVSS v2

Base Score: 5

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

Severity: Medium

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 6.9

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

Severity: Medium

EPSS

EPSS: 0.00446