---
id: "CVE-2026-64675"
page: "https://infrastack.ai/live/CVE-2026-64675"
kind: "vulnerability"
aliases: ["CVE-2026-64675"]
title: "BACnet Stack: unauthenticated UDP packet triggers out-of-bounds read"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["bacnet", "building-automation", "c", "embedded", "package"]
not_affected_if: ["no-bacnet-ip", "port-47808-filtered"]
published_at: "2026-11-13T19:19:33+00:00"
first_seen_at: "2026-11-13T19:52:09+00:00"
updated_at: "2026-11-13T19:54:16+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64675", "first_seen_at": "2026-11-13T19:52:09+00:00"}]
exploit_sources: []
---

# BACnet Stack: unauthenticated UDP packet triggers out-of-bounds read

Link for people: https://infrastack.ai/live/CVE-2026-64675 (this .md is for agents)

BACnet Stack is an open source BACnet protocol C library used in embedded building-automation devices. A single unauthenticated BACnet/IP UDP packet on port 47808 can trigger an out-of-bounds read in the lighting color decoder, which can crash or leak memory.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the BACnet Stack version in the firmware or build: unknown whether a command is given by the sources.
- Look for BACnet/IP devices or builds using the library on UDP port `47808` reachable from untrusted networks.

## Fix

- Upgrade to `1.4.5`, `1.5.1`, or `1.6.0` (the patched versions for their release lines).

## Timeline

- 2026-11-13T19:52:09+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-64675

## Documents

- [advisory] Vendor advisory: github.com https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-mmg6-p4pr-cj6h

## From the sources

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.

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