CVE-2026-34021 Lack of cryptographic protection in Wertheim SafeController 5400 enables RS-485 message sniffing and replay
Attackers can sniff and replay unencrypted RS-485 messages to spoof alarm deactivation commands on Wertheim SafeController 5400 systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-34021?
CVE-2026-34021 is a high-severity vulnerability in Wertheim SafeController 5400 Hardware for VAULT ROOMS (Safe Deposit Locker System - Microcontroller), published on 15 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The Wertheim SafeController 5400, Controller 5400 - AssemblyVersion 6.11.8130.22320, uses RS-485 communication between the server and the microcontroller without cryptographic protection. An attacker with access to the communication path between the server and the microcontroller can sniff RS-485 messages and replay previously observed messages. This can be used, for example, to spoof a "quit alarm" message and continuously deactivate the safe alarm.
Weakness: CWE-294
Which versions are affected by CVE-2026-34021?
How do I fix CVE-2026-34021?
No fix has been published for CVE-2026-34021 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-34021 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34021 exists.
Sources
Also known as GHSA-4w8g-q38j-gm8m.