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9.2
CRITICAL CVSS 4.0
CVE-2026-67276
SSH user impersonation possible in Mikrotik RouterOS
Overview
Description

RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)

Details
INFO

Published Date :

Sept. 5, 2026, 8:17 p.m.

Last Modified :

Sept. 25, 2026, 2:57 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-67276 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mikrotik routeros
2 Mikrotik routeros
: Total Affected Vendor : 1 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH [email protected]
CVSS 4.0 CRITICAL 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
CVSS 4.0 CRITICAL [email protected]
Solution
Update RouterOS to a fixed version to address SSH authentication bypass.
  • Update RouterOS to version 6.49.21 or later.
  • Update RouterOS to version 7.23.4 or later.
  • Update RouterOS to version 7.24.2 or later.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-67276.

URL Resource
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve Third Party Advisory
https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ Mitigation Third Party Advisory
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 Release Notes
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 Release Notes
https://mikrotik.com/supportsec/september-2026-vulnerability/ Vendor Advisory
https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ Exploit Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-67276 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-67276 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-67276 vulnerability anywhere in the article.

  • The Hacker News
MikroTrick Chain Let Attackers Take Over MikroTik Routers Without a Password or SSH Key

Two MikroTik RouterOS SSH vulnerabilities chained together let attackers take full administrative control of Internet-exposed routers without a password, SSH key, or completed authentication. The chai ... Read more

Published Date: Sep 23, 2026 (2 days, 12 hours ago)
  • cert.pl
MikroTrick: technical analysis, disclosure process, and the use of LLM agents

Introduction On 3 September 2026, MikroTik released patches almost simultaneously for several maintained RouterOS branches: 7.25beta3, 7.24.2, 7.23.4, and 6.49.21, and recommended installing a patched ... Read more

Published Date: Sep 22, 2026 (3 days, 14 hours ago)
  • The Cyber Express
Attackers Exploited MikroTik RouterOS Flaws a Day Before Patches Shipped

Attackers began compromising internet-exposed MikroTik routers on Sept. 2, a day before the Latvian vendor released fixes and three days before national authorities published the technical detail defe ... Read more

Published Date: Sep 07, 2026 (2 weeks, 4 days ago)
  • security.nl
MikroTik-routers via kritieke SSH-kwetsbaarheden op afstand overgenomen

Aanvallers maken actief misbruik van kritieke SSH-kwetsbaarheden om routers van fabrikant MikroTik op afstand en zonder authenticatie over te nemen, zo waarschuwen MikroTik en de Poolse overheid. Mikr ... Read more

Published Date: Sep 07, 2026 (2 weeks, 4 days ago)
  • cert.pl
Vulnerabilities in Mikrotik RouterOS software

Vulnerabilities in Mikrotik RouterOS software CVE ID CVE-2026-67276 Publication date 05 September 2026 Vendor Mikrotik Product RouterOS Vulnerable versions From 7.24 below 7.24.2From 7.0.0 below 7.23. ... Read more

Published Date: Sep 05, 2026 (2 weeks, 6 days ago)
  • cert.pl
Critical vulnerabilities in MikroTik RouterOS are being actively exploited. Immediate update recommended

The CERT Polska team has identified and coordinated the disclosure of six vulnerabilities in MikroTik RouterOS. Combining two of them allows an attacker to take full control of the device without auth ... Read more

Published Date: Sep 05, 2026 (2 weeks, 6 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-67276 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Sep. 25, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CPE Configuration OR *cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:* versions from (including) 7.24 up to (excluding) 7.24.2 *cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:* versions from (including) 7.9 up to (excluding) 7.23.4
    Added Reference Type CERT.PL: https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve Types: Third Party Advisory
    Added Reference Type CERT.PL: https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ Types: Mitigation, Third Party Advisory
    Added Reference Type CERT.PL: https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 Types: Release Notes
    Added Reference Type CERT.PL: https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 Types: Release Notes
    Added Reference Type CERT.PL: https://mikrotik.com/supportsec/september-2026-vulnerability/ Types: Vendor Advisory
    Added Reference Type CERT.PL: https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ Types: Exploit, Third Party Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 09, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-67276', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T14:48:45.722509Z'} {'id': 'CVE-2026-67276', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T00:00:00+00:00'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 08, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-67276', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T14:48:45.722509Z'}
  • CVE Modified by [email protected]

    Sep. 07, 2026

    Action Type Old Value New Value
    Changed Description RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable) RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)
    Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/67xxx/CVE-2026-67276.json">CVE-2026-67276</a>
    Removed Reference https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
  • CVE Modified by [email protected]

    Sep. 05, 2026

    Action Type Old Value New Value
    Changed Description RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions: 6.49.21 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable) RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
  • New CVE Received by [email protected]

    Sep. 05, 2026

    Action Type Old Value New Value
    Added Description RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions: 6.49.21 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable)
    Added CVSS V4.0 AV:N/AC:H/AT:N/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
    Added CWE CWE-347
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/67xxx/CVE-2026-67276.json">CVE-2026-67276</a>
    Added Reference https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
    Added Reference https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
    Added Reference https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
    Added Reference https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
    Added Reference https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
    Added Reference https://mikrotik.com/supportsec/september-2026-vulnerability/
    Added Reference https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.2
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 8.1
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact