Lantronix Autonomous Out-of-Band Devices Unauthenticated Authentication Bypass via snprintf Path Truncation

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-80155
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-22 16:18:01 UTC
Updated2026-09-24 20:17:31 UTC
DescriptionLantronix SLC8000 before firmware v9.7.0.5, SLC9000 before firmware v9.7.0.2, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain an authentication bypass vulnerability in the web management portal upload endpoint that allows unauthenticated attackers to read sensitive configuration files and upload files to arbitrary filesystem locations, leading to remote code execution. The web configuration server constructs the session cookie file path using snprintf with a fixed-size buffer; by supplying a cookie value of a specific length an attacker causes the path to truncate at the required delimiter and leverages path traversal to redirect authentication validation to an arbitrary on-disk file such as the local user database, bypassing all session checks. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.

Risk And Classification

Primary CVSS: v4.0 10 CRITICAL from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.016670000 probability, percentile 0.757660000 (date 2026-09-25)

Problem Types: CWE-22 | CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary10CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C...
4.0CNACVSS10CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
3.1[email protected]Secondary10CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
3.1CNACVSS10CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
High
Sub Integrity
High
Sub Availability
High

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA LANTRONIX SLC8000 affected 9.7.0.5 custom Not specified
CNA LANTRONIX EMG8500 affected 9.7.0.1 custom Not specified
CNA LANTRONIX EMG7500 affected 9.7.0.1 custom Not specified
CNA LANTRONIX SLB882 affected * custom Not specified
CNA LANTRONIX SLCx-03 affected * custom Not specified
CNA LANTRONIX SLCx-02 affected * custom Not specified
CNA LANTRONIX SLC9000 affected 9.7.0.2 custom Not specified

References

ReferenceSourceLinkTags
ts.lantronix.com/ftp/emg/EMG_8500/9.7.0.1R2 [email protected] ts.lantronix.com
www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-unauthent... [email protected] www.vulncheck.com
ts.lantronix.com/ftp/SLC9000/9.7.0.2R1 [email protected] ts.lantronix.com
ts.lantronix.com/ftp/emg/EMG_7500/9.7.0.1R2 [email protected] ts.lantronix.com
revrb.net/2026/09/21/revrb-lantern.html [email protected] revrb.net
ts.lantronix.com/ftp/slc8000/9.7.0.5R2 [email protected] ts.lantronix.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: RE/VRb (en)

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