Tektronix 3 Series MDO: OS command injection in SCPI file mount command
Summary
Tektronix 3 Series MDO oscilloscopes with firmware before 1.21.1 contain an OS command injection flaw in the SCPI command FILESystem:MOUNT:DRIve. Because user-supplied input is not sufficiently neutralized, a remote attacker can run arbitrary operating system commands with elevated privileges. According to the CVSS vector, the attacker needs network access and low privileges but no user interaction; the exact privilege requirement depends on the setup and is not yet confirmed by the vendor advisory.
Affected
- Tektronix 3 Series MDO firmware versions before 1.21.1 (CVE record: 0 to < 1.21.1)
- Unknown: whether other models or hardware variants are affected
Fixed in
- Firmware 1.21.1 or later (according to VulDB; verify against the Tektronix advisory TEK-PSA-002-092026)
Workaround
- No vendor-confirmed workaround known.
- Enable strict logging of all SCPI commands to detect anomalous command patterns. This is a detection measure, not a fix.
- Keep the instrument off the internet and off office networks; restrict SCPI access to a lab VLAN and known hosts.
Exploitation
- Exploited in the wild: none known. Not checked against CISA KEV or vendor threat feeds.
- Public exploit: none known (according to VulDB).
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
Our recommendation
- Inventory all 3 Series MDO units and their firmware versions.
- Read the Tektronix advisory, then upgrade to firmware 1.21.1 or later.
- Isolate instruments from untrusted networks and restrict remote-control access via SCPI.
- Review remote-access paths and the web interface; CVE-2026-111855 (path traversal in the web interface) should be checked as well.
- Re-check NVD, CISA KEV and the Tektronix advisory for changes.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Tektronix security advisory TEK-PSA-002-092026 download.tek.com
- Tektronix 3 Series MDO product page www.tek.com
- VulDB CVE-2026-111853 vuldb.com
- VulDB vulnerability 421536 vuldb.com
- Vulners NVD:CVE-2026-111853 vulners.com
- threatint CVE-2026-111853 cve.threatint.com
- threatint CVE-2026-111855 cve.threatint.com
- strix.ai CVE-2026-111853 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 15:55.
Original description (NVD)
An issue was discovered on Tektronix 3 Series MDO devices before 1.21.1. An OS command injection vulnerability exists in the FILESystem:MOUNT:DRIve SCPI command handler. Insufficient neutralization of user-supplied input allows remote attackers to execute arbitrary operating system commands with elevated privileges.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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