CVE-2026-102537

bacnet-stack BACnet/SC node always accepts a self-signed hub cert, so an attacker can MITM it

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.6, 1.5.2, and 1.6.1, bws_cli_connect() in ports/linux/websocket-cli.c loads the trusted CA cert into the libwebsockets context, then always sets LCCSCF_ALLOW_SELFSIGNED in the connection flags. So lws accepts any self-signed hub certificate, whether or not it chains to the loaded CA. A BACnet/SC node finishes the TLS handshake to a rogue hub that presents a self-signed cert. It then hands the attacker its identity (VMAC, UUID) and all later BACnet traffic. This issue has been patched in versions 1.4.6, 1.5.2, 1.6.1, and 1.7.0.

Affected Versions

References