Administrative privilege escalation via SSH argument injection
Published Sep 5, 2026 · Updated Sep 9, 2026
Argument injection in MikroTik RouterOS allows attackers to gain full administrative SSH privileges via a crafted username. The SSH login path passes the username as a positional argument to /nova/bin/login; a leading -2 is parsed as a file descriptor, allowing attacker-supplied fields to replace the trusted username and policy mask. The path requires SSH to accept the literal -2 username; observed unauthenticated takeovers chained this flaw with an SSH authentication bypass.
Summary
What happened
Argument injection in MikroTik RouterOS allows attackers to gain full administrative SSH privileges via a crafted username. The SSH login path passes the username as a positional argument to /nova/bin/login; a leading -2 is parsed as a file descriptor, allowing attacker-supplied fields to replace the trusted username and policy mask. The path requires SSH to accept the literal -2 username; observed unauthenticated takeovers chained this flaw with an SSH authentication bypass.
The record
- CVE
- CVE-2026-86060
- Published
- Sep 5, 2026
- Updated
- Sep 9, 2026
- Vendor
- MikroTik
- Product
- RouterOS
- Classifications
- CWE-88, T1068
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 2, 2026Exploitation reportedMikroTrick exploitation chain
- Sep 5, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.0.0 <6.49.21
- Affected versionversion=7.0.0 <7.23.4
- Affected versionversion=7.24 <7.24.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- RouterOS -2 PTY policy-injection proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- MikroTrick exploitation chainexploit chain
Technologies
Your stack
See the directory against your own environment.
Your stack
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