SSH session privilege manipulation via a crafted username in Mikrotik RouterOS

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-86060
StatePUBLISHED
AssignerCERT-PL
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-05 20:17:18 UTC
Updated2026-09-05 21:16:51 UTC
DescriptionRouterOS 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)

Risk And Classification

Primary CVSS: v4.0 9.2 CRITICAL from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-88 | CWE-88 CWE-88 Improper neutralization of argument delimiters in a command ('argument injection')

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.2CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS9.2CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mikrotik RouterOS affected 7.24 7.24.2 custom Not specified
CNA Mikrotik RouterOS affected 7.0.0 7.23.4 custom Not specified
CNA Mikrotik RouterOS affected 6.0.0 6.49.21 custom Not specified

References

ReferenceSourceLinkTags
cert.pl/en/posts/2026/09/mikrotik-routeros-cve [email protected] cert.pl
npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they... [email protected] npratley.net
forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 [email protected] forum.mikrotik.com
cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-activel... [email protected] cert.pl
forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 [email protected] forum.mikrotik.com
forum.mikrotik.com/t/7-24-2-stable-is-released/272800 [email protected] forum.mikrotik.com
mikrotik.com/supportsec/september-2026-vulnerability [email protected] mikrotik.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Sławomir Rozbicki (CERT.PL) (en)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report