CVE-2026-58265

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5, 1.5.1, and 1.6.0, a BACnet/SC peer can trigger a heap out-of-bounds read (up to 3 bytes), pre-authentication, in the BACnet/SC header-option decoder. bvlc_sc_decode_proprietary_option() reads the vendor-id and option-type at fixed offsets [3],[4],[5] before checking the option's declared header length, and the option-list validator never enforces a minimum length for proprietary options. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.