CVE-2026-91191

Root code execution via compromised package authentication

Published Sep 29, 2026 · Updated Sep 29, 2026

Improper package authentication in Lantronix G520 Series 2.6.0.4R6 stable allows attackers to run code as root via malicious packages. During boot, the stock done function disables OPKG signature checks before restoring packages from a writable unsigned feed; the public SDK also exposes a production signing key trusted by stable and beta firmware. Exploitation requires an attacker to supply a malicious package that the gateway subsequently installs.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper package authentication in Lantronix G520 Series 2.6.0.4R6 stable allows attackers to run code as root via malicious packages. During boot, the stock done function disables OPKG signature checks before restoring packages from a writable unsigned feed; the public SDK also exposes a production signing key trusted by stable and beta firmware. Exploitation requires an attacker to supply a malicious package that the gateway subsequently installs.

The record

CVE
CVE-2026-91191
Published
Sep 29, 2026
Updated
Sep 29, 2026
Vendor
Lantronix
Product
G520 Series
Classifications
T1553.002
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.0.4R6 stable

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Lantronix · G520 Seriesversion=2.6.0.4R6 stable

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1553.002Subvert Trust Controls: Code Signing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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