CVE-2026-109439 Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718
Remote attackers can read and persistently overwrite device configuration via unauthenticated UDP frames on Lantronix XPress-DR devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-109439?
CVE-2026-109439 is a critical missing authorization vulnerability in LANTRONIX XPress-DR, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-306
Which versions are affected by CVE-2026-109439?
How do I fix CVE-2026-109439?
No fix has been published for CVE-2026-109439 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-109439 being exploited?
There is no known exploitation of CVE-2026-109439 in the wild and no public exploit code.
Sources
Also known as GHSA-gpg6-w924-6c8v.