CVE-2026-80155 Lantronix Autonomous Out-of-Band Devices Unauthenticated Authentication Bypass via snprintf Path Truncation
Unauthenticated attackers can bypass authentication via path truncation to read configs, upload files, and execute code on Lantronix devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-80155?
CVE-2026-80155 is a critical authentication bypass vulnerability in LANTRONIX EMG7500, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-80155?
How do I fix CVE-2026-80155?
No fix has been published for CVE-2026-80155 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-80155 being exploited?
There is no known exploitation of CVE-2026-80155 in the wild and no public exploit code.
Sources
Also known as GHSA-h7c7-c453-99x2.