Vulnerability · Published Sep 29, 2026 · Assigned by icscert
CVE-2026-91191Lantronix G520 Series Cellular Gateway Improper Verification of Cryptographic Signature
High 7.5
In plain English
A high-severity security flaw in G520 Series from Lantronix. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Lantronix | G520 Series | 2.6.0.4R6 stable |
Weakness: CWE-347 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528
- https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-01
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-01.json