CVE-2026-80155
Lantronix Autonomous Out-of-Band Devices Unauthenticated Authentication Bypass via snprintf Path Truncation
Description
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 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.
INFO
Published Date :
Sept. 22, 2026, 4:18 p.m.
Last Modified :
Sept. 22, 2026, 4:18 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-80155
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update firmware on Lantronix SLC8000 devices.
- Update firmware on Lantronix EMG8500/EMG7500 devices.
- Update firmware on Lantronix SLB882/SLCx-03/SLCx-02 devices.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-80155.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80155 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80155
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-80155 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80155 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 22, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-80155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-22T15:42:37.923706Z'} -
New CVE Received by [email protected]
Sep. 22, 2026
Action Type Old Value New Value Added Description 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 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-22 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80155.json">CVE-2026-80155</a> Added Reference https://revrb.net/2026/09/21/revrb-lantern.html Added Reference https://ts.lantronix.com/ftp/emg/EMG_7500/9.7.0.1R2/ Added Reference https://ts.lantronix.com/ftp/emg/EMG_8500/9.7.0.1R2/ Added Reference https://ts.lantronix.com/ftp/slc8000/9.7.0.5R2/ Added Reference https://www.vulncheck.com/advisories/lantronix-autonomous-out-of-band-devices-unauthenticated-authentication-bypass-via-snprintf-path-truncation