CVE-2026-109439
Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718
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.
- Record
CVE-2026-109439- CVSS 4.0
- 9.3 Critical
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 - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2026-101337
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.
- Record
EUVD-2026-101337- CVSS 4.0
- 9.3 Critical
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gpg6-w924-6c8v
Lantronix XPress-DR and XPress-DR-I (CoBos-family) firmware through 8.1.0.0 contains a missing...
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.
- Record
GHSA-gpg6-w924-6c8v- CVSS 4.0
- 9.3 Critical
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-109439- CVSS 4.0
- 9.3 Critical
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-306
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-109439 is a critical vulnerability (CVSS 9.3) in Lantronix Xpress-dr, published October 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. No source names a fixed version.
References
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/advisories/lantronix-xpress-dr-unauthenticated-configuration-write-via-udp-30718
nvd.nist.gov/vuln/detail/CVE-2026-109439
github.com/advisories/GHSA-gpg6-w924-6c8v