CVE-2026-86060
SSH session privilege manipulation via a crafted username in Mikrotik RouterOS
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Description
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)
Official description from the CVE record, published by CERT-PL. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 4.0 Critical 9.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements: Present
The attack depends on certain deployment or execution conditions being present.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Vulnerable system: confidentiality: High
Serious or total effect on the secrecy of data.
Vulnerable system: integrity: High
Serious or total effect on the trustworthiness of data.
Vulnerable system: availability: High
Serious or total effect on availability.
Subsequent systems: confidentiality: None
No effect on other systems' data secrecy.
Subsequent systems: integrity: None
No effect on other systems' data trustworthiness.
Subsequent systems: availability: None
No effect on other systems' availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No measurable action is needed to get around the system's built-in security controls. The attack is repeatable. |
| Attack requirements | Present | The attack depends on certain deployment or execution conditions being present. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Vulnerable system: confidentiality | High | Serious or total effect on the secrecy of data. |
| Vulnerable system: integrity | High | Serious or total effect on the trustworthiness of data. |
| Vulnerable system: availability | High | Serious or total effect on availability. |
| Subsequent systems: confidentiality | None | No effect on other systems' data secrecy. |
| Subsequent systems: integrity | None | No effect on other systems' data trustworthiness. |
| Subsequent systems: availability | None | No effect on other systems' availability. |
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EPSS
- Score
- 0.06392 (6.4% probability)
- Percentile
- 93.7%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA Known Exploited Vulnerabilities
- Name in the catalog
- MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability
- Added to the catalog
- Sep 10, 2026
- Federal due date
- Sep 13, 2026
CISA assessment as of Sep 8, 2026
- Exploitation
- Recorded by CISA as active
- Automatable
- yes
- Technical impact
- total
Weakness (CWE)
- CWE-88Improper Neutralization of Argument Delimiters in a Command
Affected products
Mikrotik RouterOS
- affected: 7.24 up to before 7.24.2
- affected: 7.0.0 up to before 7.23.4
- affected: 6.0.0 up to before 6.49.21
References
- cert.pl/en/posts/2026/09/mikrotik-routeros-cvethird-party-advisory
- cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-router…technical-description
- npratley.net/reversing-mikrotiks-silent-patch-the-routeros-…exploit
- mikrotik.com/supportsec/september-2026-vulnerabilityvendor-advisory
- forum.mikrotik.com/t/6-49-21-long-term-is-released/272802release-notes
- forum.mikrotik.com/t/7-23-4-long-term-is-released/272801release-notes
- forum.mikrotik.com/t/7-24-2-stable-is-released/272800release-notes
Timeline
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:37 UTC. Sources and licenses