Argument-handling Flaw in RouterOS by MikroTik
CVE-2026-86060

9.2CRITICAL

Key Information:

Vendor

Mikrotik

Status
Vendor
CVE Published:
5 September 2026

Badges

👾 Exploit Exists🟡 Public PoC🦅 CISA Reported📰 News Worthy

What is CVE-2026-86060?

MikroTik's RouterOS is vulnerable due to an argument-handling flaw in the SSH login process, specifically affecting usernames that start with a prohibited character. This flaw allows an attacker to manipulate the trusted RouterOS policy mask, facilitating privilege escalation. The exploitation of this vulnerability requires an unauthorized SSH session targeting the RouterOS login helper, presenting a significant risk to network security. The issue has been rectified in versions 6.49.21 (Long-term), 7.23.4 (Long-term), and 7.24.2 (Stable).

CISA has reported CVE-2026-86060

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed CVE-2026-86060 as being exploited but is not known by the CISA to be used in ransomware campaigns. This is subject to change at pace

The CISA's recommendation is: 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.

Affected Version(s)

RouterOS 7.24 < 7.24.2

RouterOS 7.0.0 < 7.23.4

RouterOS 6.0.0 < 6.49.21

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

News Articles

MikroTrick Chain Let Attackers Take Over MikroTik Routers Without a Password or SSH Key

Attackers chained two RouterOS SSH flaws to gain full admin access on Internet-exposed MikroTik routers before patches shipped.

3 days ago

MikroTik RouterOS Vulnerabilities Actively Exploited via SSH | eSecurity Planet

Attackers are actively exploiting MikroTik RouterOS flaws for unauthenticated router takeover. Here are the fixes, indicators of compromise, and post-patch checks. Attackers are exploiting MikroTik RouterOS SSH flaws for full router takeover. See fixed versions, attack indicators, and post-update ch...

3 weeks ago

References

CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🦅

    CISA Reported

  • 📰

    First article discovered by Esecurity Planet

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Sławomir Rozbicki (CERT.PL)
.