---
cve: "CVE-2026-80155"
severity: "CRITICAL"
cvss: 10.0
epss: "1%"
vendor: "Lantronix"
kev: false
exploited: false
published: "2026-09-22 16:18:01"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-29T16:00:51+01:00"
---

# CVE-2026-80155

> 10.0 CRITICAL

## Beschreibung

Lantronix 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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-09-24 19:11:02
- CNA-CVSS: **10.0** (`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`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **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.

## Angriffsmuster (CAPEC)

- [CAPEC-64 — Using Slashes and URL Encoding Combined to Bypass Validation Logic](https://capec.mitre.org/data/definitions/64.html) _(Severity: High)_
- [CAPEC-76 — Manipulating Web Input to File System Calls](https://capec.mitre.org/data/definitions/76.html) _(Severity: Very High)_
- [CAPEC-78 — Using Escaped Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/78.html) _(Severity: High)_
- [CAPEC-79 — Using Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/79.html) _(Severity: High)_
- [CAPEC-126 — Path Traversal](https://capec.mitre.org/data/definitions/126.html) _(Severity: Very High)_

## Referenzen

- <https://revrb.net/2026/09/21/revrb-lantern.html>
- <https://ts.lantronix.com/ftp/slc8000/9.7.0.5R2/>
- <https://ts.lantronix.com/ftp/emg/EMG_8500/9.7.0.1R2/>
- <https://ts.lantronix.com/ftp/emg/EMG_7500/9.7.0.1R2/>
- <https://ts.lantronix.com/ftp/SLC9000/9.7.0.2R1/>
- <https://www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-unauthenticated-authentication-bypass-via-snprintf-path-truncation>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-80155/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_