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TI-2026-30088 Aliases CVE-2026-41502

BACnet Stack: Off-by-One Out-of-Bounds Read in ReadPropertyMultiple Object ID Decoder

Priority HIGH 77CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00401 34th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed bacnet-stack (bacnet-stack): 1.4.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
bacnet-stackbacnet-stack1.4.0 to before 1.4.31.4.3Patch availableCNA
  • bacnet-stack Vendorbacnet-stack Affected 1.4.0 to before 1.4.3 Fixed in 1.4.3 Patch available CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:a:bacnetstack:bacnet_stack:*:*:*:*:*:*:*:*1.4.0 to before 1.4.3Vulnerablebacnet-stack
cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc1:*:*:*:*:*:*1.5.0 rc1Vulnerablebacnet-stack
cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc2:*:*:*:*:*:*1.5.0 rc2Vulnerablebacnet-stack
cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc3:*:*:*:*:*:*1.5.0 rc3Vulnerablebacnet-stack
  • cpe:2.3:a:bacnetstack:bacnet_stack:*:*:*:*:*:*:*:* Versions 1.4.0 to before 1.4.3 Vulnerable ·bacnet-stack
  • cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc1:*:*:*:*:*:* Versions 1.5.0 rc1 Vulnerable ·bacnet-stack
  • cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc2:*:*:*:*:*:* Versions 1.5.0 rc2 Vulnerable ·bacnet-stack
  • cpe:2.3:a:bacnetstack:bacnet_stack:1.5.0:rc3:*:*:*:*:*:* Versions 1.5.0 rc3 Vulnerable ·bacnet-stack

Remediation

  • Fix · CNA bacnet-stack (bacnet-stack) Fixed in 1.4.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-41502

References

Exploit 1

  • TI-2026-30089 BACnet Stack: Out-of-Bounds Read in ReadPropertyMultiple Property Decoder via Deprecated Tag Parser CVSS 4.0HIGH 8.7
  • TI-2026-30063 BACnet Stack: Out-of-Bounds Read in WritePropertyMultiple Decoder via Deprecated Tag Parser CVSS 4.0HIGH 8.7
  • TI-2026-21234 BACnet Stack WriteProperty decoding length underflow leads to OOB read and crash CVSS 4.0HIGH 7.8
  • TI-2026-17579 BACnet Stack Improperly Limits Pathnames to a Restricted Directory CVSS 3.1HIGH 7.5
  • TI-2025-41018 BACnet-stack MS/TP reply matcher OOB read CVSS 3.1HIGH 7.5
  • TI-2026-29061 BACnet Stack: Undefined-behavior signed left shift in `decode_signed32()` CVSS 3.1LOW 3.7
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences