CVE-2026-41502

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3
https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3

Configurations

No configuration.

History

25 Apr 2026, 03:16

Type	Values Removed	Values Added
References	~~() https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3 -~~	() https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3 -

24 Apr 2026, 20:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-24 20:16

Updated : 2026-04-25 03:16

NVD link : CVE-2026-41502

Mitre link : CVE-2026-41502

CVE.ORG link : CVE-2026-41502

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

CWE-193

Off-by-one Error

{"id": "CVE-2026-41502", "cveTags": [], "metrics": {"cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-04-24T20:16:28.563", "references": [{"url": "https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3", "source": "security-advisories@github.com"}, {"url": "https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7545-3fpx-4xw3", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-193"}]}], "descriptions": [{"lang": "en", "value": "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) \u2014 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."}], "lastModified": "2026-04-25T03:16:05.130", "sourceIdentifier": "security-advisories@github.com"}