CVE-2026-91191 (GCVE-0-2026-91191)
Vulnerability from cvelistv5 – Published: 2026-09-29 21:04 – Updated: 2026-09-29 21:04
VLAI
EPSS
VEX
Title
Lantronix G520 Series Cellular Gateway Improper Verification of Cryptographic Signature
Summary
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.
Severity
CWE
Assigner
References
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Lantronix | G520 Series |
Affected:
2.6.0.4R6 stable
|
guessed |
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"value": "The device\u0027s 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."
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"value": "The device\u0027s 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."
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"metrics": [
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{
"url": "https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/"
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{
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-01"
},
{
"url": "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-01.json"
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"solutions": [
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"value": "Lantronix has addressed the reported issues with release version 2.6.0.7R6 which is available on their website.\u003cbr\u003e\u003cdiv\u003e\u003ca href=\"https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528\"\u003ehttps://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528\u003c/a\u003e\u003c/div\u003e\u003cdiv\u003e\u003cbr\u003e\u003c/div\u003e\u003cdiv\u003e\n\u003cp\u003eFor more information, see the Lantronix Vulnerability Library.\u003cbr\u003e\u003ca href=\"https://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/\"\u003ehttps://www.lantronix.com/technical-support/security-updates/vulnerability-disclosure-policy/vulnerability-library/\u003c/a\u003e\u003c/p\u003e\u003cp\u003eFor more information or technical assistance, contact Lantronix support: Support@lantronix.com\u003cbr\u003e\u003ca href=\"mailto:Support@lantronix.com\"\u003emailto:Support@lantronix.com\u003c/a\u003e\u003c/p\u003e\n\n\u003c/div\u003e"
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}
],
"source": {
"advisory": "ICSA-26-272-01",
"discovery": "EXTERNAL"
},
"title": "Lantronix G520 Series Cellular Gateway Improper Verification of Cryptographic Signature",
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"assignerShortName": "icscert",
"cveId": "CVE-2026-91191",
"datePublished": "2026-09-29T21:04:52.546Z",
"dateReserved": "2026-09-17T19:24:31.384Z",
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"state": "PUBLISHED"
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}
],
"id": "CVE-2026-91191",
"lastModified": "2026-09-29T22:19:03.727",
"metrics": {
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"references": [
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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