CVE-2026-41503 Details
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 ReadPropertyMultiple service property decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending an RPM request with a truncated property list. The vulnerability stems from rpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function at src/bacnet/rpm.c:344, which accepts no buffer length parameter and reads blindly from whatever pointer it receives. A crafted BACnet/IP packet with a 1-byte property payload containing an extended tag marker (0xF9) causes the decoder to read 1 byte past the end of the buffer, 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.
An out-of-bounds read vulnerability has been identified in BACnet Stack versions 1.5.0.rc1 and 1.4.0-1.4.2. The issue arises in the ReadPropertyMultiple service property decoder, where unauthenticated remote attackers can send a request with a truncated property list. This exploitation allows reading past allocated buffer boundaries, leading to crashes on embedded BACnet devices. The vulnerability is caused by the rpm_decode_object_property() function calling the deprecated decode_tag_number_and_value() function, which lacks buffer length parameters and reads blindly from received pointers. A crafted BACnet/IP packet can trigger the out-of-bounds read by exploiting the extended tag marker.
Users can update to BACnet Stack version 1.5.0 or 1.4.3, both of which include the necessary fix.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 27, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-5w2v-mwqj-pr2c | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-5w2v-mwqj-pr2c | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-125 | Out-of-bounds Read | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| bacnetstack bacnet stack | >= 1.4.0, < 1.4.3 1.5.0 rc1 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 28, 2026 | Initial Analysis | [email protected] |
| Apr 27, 2026 | CVE Modified | CISA-ADP |
| Apr 24, 2026 | New CVE Received | [email protected] |