CVE-2026-80156: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-hmch-26g2-q5qx
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CVSS 9.1
CWE-22
Published
Advisory Summary

CVE-2026-80156 is a CRITICAL (CVSS 9.1) security vulnerability vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-80156 at a Glance

CVE Identifier CVE-2026-80156
GHSA Identifier GHSA-hmch-26g2-q5qx
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-80156

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-80156, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Lantronix SLC8000 before firmware v9.7.0.5, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a path traversal vulnerability in the web management portal upload endpoint that allows authenticated attackers to write arbitrary data to any location on the device's filesystem, leading to remote code execution. The upload filename validation strips backslash characters but does not subsequently check for forward slashes when a backslash is detected; by supplying a filename containing both characters an attacker writes outside the intended upload directory to any writable path. 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.

References

NVD — CVE-2026-80156 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-80156
revrb.net/2026/09/21/revrb-la... WEB
https://revrb.net/2026/09/21/revrb-lantern.html
ts.lantronix.com/ftp/slc9000/9.7.0.2... WEB
https://ts.lantronix.com/ftp/SLC9000/9.7.0.2R1
ts.lantronix.com/ftp/emg/emg_7500/9.... WEB
https://ts.lantronix.com/ftp/emg/EMG_7500/9.7.0.1R2
ts.lantronix.com/ftp/emg/emg_8500/9.... WEB
https://ts.lantronix.com/ftp/emg/EMG_8500/9.7.0.1R2
ts.lantronix.com/ftp/slc8000/9.7.0.5... WEB
https://ts.lantronix.com/ftp/slc8000/9.7.0.5R2
www.vulncheck.com/advisories/lantroni... WEB
https://www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-arbitrary-file-write-via-upload-filename-validation-bypass

Frequently Asked Questions

What is CVE-2026-80156?
CVE-2026-80156 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-80156?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-80156?
CVE-2026-80156 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-80156?
CVE-2026-80156 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Maven dependencies for CVE-2026-80156?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hmch-26g2-q5qx",
  "modified" : "2026-09-24T21:32:32Z",
  "published" : "2026-09-22T18:33:29Z",
  "aliases" : [ "CVE-2026-80156" ],
  "details" : "Lantronix SLC8000 before firmware v9.7.0.5, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a path traversal vulnerability in the web management portal upload endpoint that allows authenticated attackers to write arbitrary data to any location on the device's filesystem, leading to remote code execution. The upload filename validation strips backslash characters but does not subsequently check for forward slashes when a backslash is detected; by supplying a filename containing both characters an attacker writes outside the intended upload directory to any writable path. 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-80156"
  }, {
    "type" : "WEB",
    "url" : "https://revrb.net/2026/09/21/revrb-lantern.html"
  }, {
    "type" : "WEB",
    "url" : "https://ts.lantronix.com/ftp/SLC9000/9.7.0.2R1"
  }, {
    "type" : "WEB",
    "url" : "https://ts.lantronix.com/ftp/emg/EMG_7500/9.7.0.1R2"
  }, {
    "type" : "WEB",
    "url" : "https://ts.lantronix.com/ftp/emg/EMG_8500/9.7.0.1R2"
  }, {
    "type" : "WEB",
    "url" : "https://ts.lantronix.com/ftp/slc8000/9.7.0.5R2"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-arbitrary-file-write-via-upload-filename-validation-bypass"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-22T16:18:02Z"
  }
}