CVE-2026-41475: Bacnetstack Bacnet Stack

Critical severity, CVSS 9.1. EPSS: 0.7% chance of exploitation in the next 30 days.

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's WritePropertyMultiple service decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending a truncated WPM request. The vulnerability stems from wpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function, which performs no bounds checking on the input buffer. A crafted BACnet/IP packet with a truncated property payload causes the decoder to read 1-7 bytes past the end of the buffer, leading to crashes or information disclosure on embedded BACnet devices. This vulnerability is fixed in 1.4.3.

Affected products

• Bacnetstack Bacnet Stack: from 1.4.0, before 1.4.3 (fixed in 1.4.3); version 1.5.0 only

Published 2026-04-24. Last modified 2026-06-17.