CVE-2026-109439

CRITICAL 9.8

Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

Lantronix XPress-DR and XPress-DR-I (CoBos-family) firmware through 8.1.0.0 contains a missing authentication vulnerability that allows remote attackers to read and persistently overwrite device configuration by sending crafted frames to the unauthenticated UDP configuration protocol on port 30718. Attackers can send a type 0xF8 query to read live configuration data and a type 0xFD frame with exactly 0x78 body bytes to rewrite the device IP address and serial-channel forwarding records, causing changes to commit to EEPROM and persist across reboots. The XPress-DR product series reached end-of-life/end-of-support in February 2025.

CWE	CWE-306
Vendor	lantronix
Product	xpress-dr
Published	Oct 14, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

LANTRONIX / XPress-DR

0 ≤ 8.1.0.0

LANTRONIX / XPress-DR-I

0 ≤ 8.1.0.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

cdn.lantronix.com: https://cdn.lantronix.com/wp-content/uploads/pdf/PCN-753-Rev-B-EOL-Notice-XPRESS.pdf?xnotes__c=I%20am%20interested%20in%20the%20XPress%20DR%20/%20XPress%20DR-IAP. vulncheck.com: https://www.vulncheck.com/advisories/lantronix-xpress-dr-unauthenticated-configuration-write-via-udp-30718

Credits

D6fault