CVE-2026-109439

critical

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.

References

https://www.vulncheck.com/advisories/lantronix-xpress-dr-unauthenticated-configuration-write-via-udp-30718

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-101337

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.

Details

Source: Mitre, NVD

Published: 2026-10-14

Updated: 2026-10-14

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base 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

Severity: Critical

EPSS

EPSS: 0.00618