CVE-2026-64675

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5 and 1.5.1, a single unauthenticated BACnet/IP UDP datagram (port 47808) triggers an out-of-bounds read in xy color decode() (src/bacnet/lighting.c), reachable pre-authentication through two default-registered service handlers: the UnconfirmedRequest WriteGroup service (0x0A) and Confirmed WriteProperty on a BACnetXYColor-typed property. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.