CVE-2026-80154

high

Description

All firmware versions of Lantronix SLC8000, SLC9000, EMG8500, EMG7500, SLB882, SLCx-03, and SLCx-02 contain an authentication bypass vulnerability in the web management portal that allows unauthenticated attackers to derive valid session tokens of logged-in users and bypass source IP and User-Agent validation. Session tokens are generated deterministically from the device model and the current time at one-second resolution, resulting in a small enumerable set of possible active tokens. Attackers can construct a crafted URI that exploits file extension handling in the web server path routing to bypass per-session source-address validation, then use a derived token from a different source address to gain elevated privileges on the affected device and potentially impact downstream serial-attached devices.

References

https://www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-predictable-session-token-with-validation-bypass

https://revrb.net/2026/09/21/revrb-lantern.html

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-84520

Details

Source: Mitre, NVD

Published: 2026-09-22

Updated: 2026-09-24

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: 9.6

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

Severity: Critical

CVSS v4

Base Score: 8.9

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Severity: High

EPSS

EPSS: 0.00627