CVE-2026-91191

High

Description

The device's update mechanism includes conditions that allow unauthorized software packages to be accepted as authentic. During the boot process, the stock done function disables signature verification in the OPKG configuration before restoring optional packages from a writable, unsigned feed. Separately, the publicly distributed SDK contains the production private key whose corresponding public key is trusted by both stable and beta firmware builds. Either issue undermines package authenticity, and together they allow an attacker to provide packages that appear valid to the system. Even if signature enforcement is restored, the exposed production key enables an attacker to generate signatures that the device will continue to trust. An attacker who can supply a malicious package may be able to execute arbitrary code with root privileges during installation.

SeverityHigh
CVSS7.5
Exploit probability—
ProductG520 Series
PublishedSep 29, 2026
First seenSep 29, 2026
Weakness typeCWE-347CWE-347

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Lantronix G520 Series2.6.0.4R6 stable—

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