Cyber Posture

CVE-2026-41475

CriticalPublic PoC

Published: 24 April 2026

Published
24 April 2026
Modified
28 April 2026
KEV Added
Patch
CVSS Score 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0027 49.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

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…

more

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.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly requires timely remediation of the identified out-of-bounds read flaw in BACnet Stack by applying the version 1.4.3 patch.

prevent

Mandates bounds checking and validation of BACnet/IP input buffers in the WritePropertyMultiple decoder to prevent processing truncated or malformed requests.

prevent

Implements runtime memory protections to detect and prevent unauthorized out-of-bounds reads beyond allocated buffers in the vulnerable decoder.

Security SummaryAI

CVE-2026-41475 is an out-of-bounds read vulnerability (CWE-125) affecting BACnet Stack, an open-source C library implementing the BACnet protocol for embedded systems, in versions prior to 1.4.3. The flaw resides in the WritePropertyMultiple (WPM) service decoder, where the wpm_decode_object_property() function calls the deprecated decode_tag_number_and_value() without performing bounds checks on the input buffer.

Unauthenticated remote attackers can exploit the vulnerability over the network by sending a crafted BACnet/IP packet containing a truncated WPM request with a malformed property payload. This triggers the decoder to read 1-7 bytes past the end of the allocated buffer, potentially causing application crashes (denial of service) or sensitive information disclosure from adjacent memory on vulnerable embedded BACnet devices. The issue carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

The vulnerability is fixed in BACnet Stack version 1.4.3. The GitHub security advisory (GHSA-cvv4-v3g6-4jmv) provides details on the patch, and security practitioners should prioritize updating affected systems to mitigate remote exploitation risks.

Details

CWE(s)

Affected Products

bacnetstack
bacnet stack
1.5.0 · 1.4.0 — 1.4.3

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CVE describes unauthenticated remote exploitation of a public-facing BACnet/IP service (T1190) leading to application crashes via out-of-bounds read (T1499.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References