CVE-2026-86060: MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability
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.
Other sources
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)
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MikroTik RouterOSto a version that resolves this vulnerability.Fixed in 6.49.21 - Upgrade
Upgrade
MikroTik RouterOSto a version that resolves this vulnerability.Fixed in 7.23.4 - Upgrade
Upgrade
MikroTik RouterOSto a version that resolves this vulnerability.Fixed in 7.24.2 - Compensating control
Evaluate each asset’s internet exposure and ensure adherence to CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk guidance; for internet-accessible systems, limit access so unauthenticated SSH sessions cannot reach the RouterOS login helper.
Event History
Frequently Asked Questions
Which deployments are exposed to exploitation?
Deployments where an unauthenticated SSH session can reach the RouterOS login helper are exposed. The issue affects MikroTik RouterOS versions earlier than the fixed releases in their respective trains.
What does an attacker need to exploit this issue?
An attacker needs network access to establish an unauthenticated SSH session to the RouterOS login helper. The flaw is triggered through a crafted username beginning with a prohibited character.
Which RouterOS releases contain the fix?
The issue was fixed in RouterOS 6.49.21 (Long-term), 7.23.4 (Long-term), and 7.24.2 (Stable).
How can exposure be reduced if an update cannot be applied immediately?
Restrict unauthenticated SSH access so that attackers cannot reach the RouterOS login helper. The provided data does not identify additional mitigations or indicators of compromise.