Original Article Summary

View CSAF Summary Successful exploitation of these vulnerabilities could allow an attacker to replace software and execute arbitrary code with root privileges. The following versions of Lantronix G520 Series Cellular Gateway are affected: G520 Series 2.6.0.4R6_stable (CVE-2026-84409, CVE-2026-91191) CVSS Vendor Equipment Vulnerabilities v3 7.5 Lantronix Lantronix G520 Series Cellular Gateway Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), Improper Verification of Cryptographic Signature Background Critical Infrastructure Sectors: Transportation Systems, Energy, Water and Wastewater Systems Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-84409 The device's update mechanism retrieves metadata for software updates over an unencrypted HTTP connection and stores portions of that metadata for later use. A management interface subsequently returns this stored value in a JSON response, and the web interface responsible for displaying update information inserts that value directly into the page as HTML. This behavior allows attacker‑controlled metadata to be interpreted as script content. In addition, the same authenticated origin provides an interface capable of executing system‑level commands with root privileges. An attacker able to influence update metadata could exploit these conditions to execute arbitrary code within the administrative context of the device. View CVE Details Affected Products Lantronix G520 Series Cellular Gateway Vendor: Lantronix Product Version: Lantronix G520 Series: 2.6.0.4R6_stable Product Status: known_affected Remediations Mitigation 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 Mitigation For more information, see the Lantronix Vulnerability Library. https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/ Mitigation For more information or technical assistance, contact Lantronix support: Support@lantronix.com mailto:Support@lantronix.com Relevant CWE: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H 4.0 7.7 HIGH CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N CVE-2026-91191 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. View CVE Details Affected Products Lantronix G520 Series Cellular Gateway Vendor: Lantronix Product Version: Lantronix G520 Series: 2.6.0.4R6_stable Product Status: known_affected Remediations Mitigation 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 Mitigation For more information, see the Lantronix Vulnerability Library. https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/ Mitigation For more information or technical assistance, contact Lantronix support: Support@lantronix.com mailto:Support@lantronix.com Relevant CWE: CWE-347 Improper Verification of Cryptographic Signature Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H 4.0 7.7 HIGH 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 Acknowledgments Ievgen Bondarenko reported these vulnerabilities to CISA. Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. Revision History Initial Release Date: 2026-09-29 Date Revision Summary 2026-09-29 1 Initial Publication Legal Notice and Terms of Use