Detections
Analytics
MikroTik RouterOS 6.x < 6.49.21 / 7.0.x < 7.23.4 / 7.24.x < 7.24.2 Multiple Vulnerabilities
critical Nessus Plugin ID 344588
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Synopsis
The remote networking device is affected by multiple vulnerabilities.Description
According to its self-reported version, the remote networking device is running a version of MikroTik RouterOS 6.x prior to 6.49.21, or 7.0.x prior to 7.23.4, or 7.24.x prior to 7.24.2. It is, therefore, affected by multiple vulnerabilities :- RouterOS accepts a 'related' btest connection before the corresponding primary session has completed authentication. An unauthenticated client can use this state to start an IPv4 UDP test. With 'random-data=false', the sender transmits an uninitialized tail from a kernel packet buffer. A separate unchecked, inverted packet-size interval causes unsigned integer underflow, anomalously large fragmented output, and can restart the RouterOS kernel. (CVE-2026-67277)
- 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. (CVE-2026-86060)
- RouterOS SSH enters the connection protocol after a client-requested rekey even though user authentication was never attempted, allowing an unauthenticated client to open a session channel and send an exec request. On affected builds the server dispatches the command, enabling unauthenticated creation, overwrite, and reconstruction of files in the RouterOS managed file namespace, including support files containing configuration and diagnostic data.
(CVE-2026-67279)
Note that Nessus has not tested for this issue but has instead relied only on the router's self-reported version number.
Solution
Upgrade to MikroTik RouterOS 6.49.21, 7.23.4, 7.24.2 or later.See Also
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
https://mikrotik.com/supportsec/september-2026-vulnerability/
Plugin Details
Severity: Critical
ID: 344588
File Name: mikrotik_6_49_21.nasl
Version: 1.6
Type: Remote
Family: Misc.
Published: 9/10/2026
Updated: 9/26/2026
Configuration: Enable thorough checks (optional)
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Critical
Score: 9.5
Percentile: 99.87
CVSS v2
Risk Factor: Critical
Base Score: 10
Temporal Score: 8.3
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score Source: CVE-2026-86060
CVSS v3
Risk Factor: Critical
Base Score: 9.8
Temporal Score: 9.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:F/RL:O/RC:C
CVSS v4
Risk Factor: Critical
Base Score: 9.2
Threat Score: 9.2
Threat Vector: CVSS:4.0/E:A
Vector: 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
Vulnerability Information
CPE: cpe:/o:mikrotik:routeros
Required KB Items: MikroTik/RouterOS/Version
Exploit Available: true
Exploit Ease: Exploits are available
Patch Publication Date: 9/3/2026
Vulnerability Publication Date: 9/5/2026
CISA Known Exploited Vulnerability Due Dates: 9/13/2026, 9/28/2026
Reference Information
CVE: CVE-2026-67277, CVE-2026-67279, CVE-2026-86060
IAVA: 2026-A-0941