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.
Advisories

No advisories yet.

Fixes

Solution

Lantronix has addressed the reported issues with release version 2.6.0.7R6 which is available on their website. https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528 For more information, see the Lantronix Vulnerability Library. https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/ For more information or technical assistance, contact Lantronix support: [email protected] mailto:[email protected]


Workaround

No workaround given by the vendor.

History

Tue, 29 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
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.
Title Lantronix G520 Series Cellular Gateway Improper Verification of Cryptographic Signature
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: icscert

Published:

Updated: 2026-09-29T21:04:52.546Z

Reserved: 2026-09-17T19:24:31.384Z

Link: CVE-2026-91191

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-29T22:19:03.727

Modified: 2026-09-29T22:19:03.727

Link: CVE-2026-91191

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses