MikroTik RouterOS Missing Authentication for Critical Function (CVE-2026-67277)

high Tenable OT Security Plugin ID 506059

Synopsis

The remote OT asset is affected by a vulnerability.

Description

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. This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 506059

File Name: tenable_ot_mikrotik_CVE-2026-67277.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 10/5/2026

Updated: 10/5/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.5

Percentile: 96.46

CVSS v3

Risk Factor: High

Base Score: 8.2

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Vulnerability Information

CPE: cpe:/o:mikrotik:routeros:6, cpe:/o:mikrotik:routeros:7

Required KB Items: Tenable.ot/MikroTik

Patch Publication Date: 9/5/2026

Vulnerability Publication Date: 9/5/2026

Reference Information

CVE: CVE-2026-67277

CWE: 306

Detections

Analytics