---
id: CVE-2026-111855
title: An issue was discovered on Tektronix 3 Series MDO devices before 1.21.1
summary: >-
  An issue was discovered on Tektronix 3 Series MDO devices before 1.21.1. A
  path traversal vulnerability exists in the web management interface of the
  device. Insufficient validation of user-supplied file paths allows remote
  attackers to …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-22
vendor: Tektronix
product: 3 Series MDO
affected:
  - 3_series_mdo < 1.21.1
published: '2026-10-17'
updated: '2026-10-17'
sourceUpdated: '2026-10-17T02:09:21.352Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111855'
references:
  - url: 'https://www.tek.com/en/products/oscilloscopes/3-series-mdo'
  - url: 'https://download.tek.com/document/TEK-PSA-002-092026.pdf'
tags:
  - cve.org
ingestedAt: '2026-10-17T02:57:58.446Z'
epss: 0.00492
epssPercentile: 0.40952
---

## Overview

An issue was discovered on Tektronix 3 Series MDO devices before 1.21.1. A path traversal vulnerability exists in the web management interface of the device. Insufficient validation of user-supplied file paths allows remote attackers to read arbitrary files accessible to the application. Depending on configuration, exploitation may be possible without authentication.

## Affected

- `3_series_mdo < 1.21.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.