bacnet-stack BACnet Stack up to 1.4.2 ReadPropertyMultiple Service src/bacnet/rpm.c rpm_decode_object_id out-of-bounds

Summaryinfo

A vulnerability, which was classified as problematic, has been found in bacnet-stack BACnet Stack up to 1.4.2. The affected element is the function rpm_decode_object_id of the file src/bacnet/rpm.c of the component ReadPropertyMultiple Service. This manipulation causes out-of-bounds. This vulnerability appears as CVE-2026-41502. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in bacnet-stack BACnet Stack up to 1.4.2 and classified as problematic. Affected by this vulnerability is the function rpm_decode_object_id of the file src/bacnet/rpm.c of the component ReadPropertyMultiple Service. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. The summary by CVE is:

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an off-by-one out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service decoder allows unauthenticated remote attackers to read one byte past an allocated buffer boundary by sending a crafted RPM request with a truncated object identifier. The vulnerability is in rpm_decode_object_id(), which checks apdu_len < 5 but then accesses all 6 byte positions (indices 0-5) — consuming 1 byte for the context tag, 4 bytes for the object ID, then reading apdu[5] for the opening tag check. A 5-byte input passes the length check but causes a 1-byte OOB read, leading to crashes on embedded BACnet devices. The vulnerability exists in src/bacnet/rpm.c and affects any deployment that enables the ReadPropertyMultiple confirmed service handler (enabled by default in the reference server). This vulnerability is fixed in 1.4.3.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-41502 since 04/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.4.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-25624). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• bacnet-stack

Name

• BACnet Stack

Version

• 1.4.0
• 1.4.1
• 1.4.2

CPE 2.3info

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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