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.

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Advisories

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Fixes

Solution

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Workaround

To mitigate this vulnerability, connect to the device via Telnet or CLI, open the Security settings (option 6), set “Disable port 77FEh” to Y, then save and exit to disable port 30718 (77FEh).

History

Wed, 14 Oct 2026 17:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-14T16:45:49.338Z

Reserved: 2026-10-12T15:52:36.683Z

Link: CVE-2026-109439

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T17:18:23.253

Modified: 2026-10-14T17:18:23.253

Link: CVE-2026-109439

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses