---
id: "CVE-2026-86060"
kind: "vulnerability"
aliases: ["CVE-2026-86060"]
title: "mikrotik routeros: RouterOS contains an argument-handling flaw in the SSH login path involving usernames that begin with a prohibited\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "resolved"
category: "infrastructure"
products: [{"name": "MikroTik RouterOS", "fixed": ["6.49.21", "7.23.4", "7.24.2", "7.25beta3"], "affected": "6.0.0 to before 6.49.21; 7.0.0 to before 7.23.4; 7.24 before 7.24.2", "ecosystem": "vendor"}, {"name": "mikrotik routeros", "fixed": ["6.49.21"], "affected": ">= 6.0, < 6.49.21", "ecosystem": "vendor"}, {"name": "mikrotik routeros", "fixed": ["7.23.4"], "affected": ">= 7.0, < 7.23.4", "ecosystem": "vendor"}, {"name": "mikrotik routeros", "fixed": ["7.24.2"], "affected": ">= 7.24, < 7.24.2", "ecosystem": "vendor"}, {"name": "MikroTik RouterOS", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "mikrotik", "network-gear", "privilege-escalation", "routeros", "self-hosted", "ssh"]
not_affected_if: ["fixed-version"]
published_at: "2026-09-05T20:17:18+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:50+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-86060", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-23T21:38:16+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86060", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# mikrotik routeros: RouterOS contains an argument-handling flaw in the SSH login path involving usernames that begin with a prohibited…

MikroTik RouterOS does not neutralize argument delimiters in a command, letting an attacker change the trusted RouterOS policy mask and gain higher privileges. CISA lists it as actively exploited and CERT Polska published a technical analysis.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:MikroTik RouterOS affected 6.0.0 to before 6.49.21; 7.0.0 to before 7.23.4; 7.24 before 7.24.2 fixed 6.49.21, 7.23.4, 7.24.2, 7.25beta3
- vendor:mikrotik routeros affected >= 6.0, < 6.49.21 fixed 6.49.21
- vendor:mikrotik routeros affected >= 7.0, < 7.23.4 fixed 7.23.4
- vendor:mikrotik routeros affected >= 7.24, < 7.24.2 fixed 7.24.2
- vendor:MikroTik RouterOS affected ? fixed ?

## How to check

Check the installed RouterOS version (/system resource print) and compare it to the fixed versions.

## Fix

Upgrade RouterOS to 6.49.21, 7.23.4, or 7.24.2 or later, per the MikroTik advisory.
Follow CISA BOD 26-04 guidance and the forensics triage requirements if exposure is suspected.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-86060
- 2026-10-23T21:38:16+00:00 analyst — Vendor page (MikroTik Sep 3 2026, updated Oct 6) + CERT.pl analysis + CVE record read. Part of the MikroTrick chain with CVE-2026-67279 (unauth SSH). Exploited since ~Sep 2; no public PoC link found (CERT.pl gave vendor a PoC privately). CVSS 4.0 9.2 per CVE record; severity raised to critical on that and exploitation.
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-86060

## Documents

- [advisory] MikroTik: September 2026 vulnerability https://mikrotik.com/supportsec/september-2026-vulnerability/
- [advisory] CVE Record CVE-2026-86060 https://www.cve.org/CVERecord?id=CVE-2026-86060
- [describes] CERT Polska: MikroTrick technical analysis https://cert.pl/en/posts/2026/09/mikrotrick-technical-analysis/
- [mentions] BleepingComputer: Hackers exploit new MikroTik RouterOS flaws https://www.bleepingcomputer.com/news/security/hackers-exploit-new-mikrotik-routeros-flaws-to-hijack-routers/
- [mentions] CERT.pl: MikroTrick, RouterOS vulnerabilities actively exploited https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/

## From the sources

MikroTik RouterOS contains an improper neutralization of argument delimiters in a command vulnerability which allows an attacker to change the trusted RouterOS policy mask, leading to privilege escalation.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_