CVE-2026-46677

BACnet Stack: Client-Side Out-of-Bounds Read in AtomicReadFile-ACK Record-Access Handling via RecordCount / fileData[] Mismatch

Published Nov 12, 2026 CVSS 3.1 · 6.5 Medium EPSS n/a KEV · Not listed
Description
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, there is a client-side out-of-bounds read in the AtomicReadFile-ACK record-access handling path. The issue is caused by a mismatch between a remote returnedRecordCount value and the fixed local fileData[] array capacity in BACNET_ATOMIC_READ_FILE_DATA. The ACK decode path preserves the remote RecordCount, discards storage for excess records without truncating that count, and a downstream sink later iterates over the original RecordCount and indexes fileData[i] out of bounds. This issue has been patched in versions 1.4.4 and 1.5.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
First Time appeared Bacnetstack
Bacnetstack bacnet Stack
Vendors & Products Bacnetstack
Bacnetstack bacnet Stack
Type Values Removed Values Added
Description BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, there is a client-side out-of-bounds read in the AtomicReadFile-ACK record-access handling path. The issue is caused by a mismatch between a remote returnedRecordCount value and the fixed local fileData[] array capacity in BACNET_ATOMIC_READ_FILE_DATA. The ACK decode path preserves the remote RecordCount, discards storage for excess records without truncating that count, and a downstream sink later iterates over the original RecordCount and indexes fileData[i] out of bounds. This issue has been patched in versions 1.4.4 and 1.5.1.
Title BACnet Stack: Client-Side Out-of-Bounds Read in AtomicReadFile-ACK Record-Access Handling via RecordCount / fileData[] Mismatch
Weaknesses CWE-125
CWE-130
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 12, 2026, 8:01 PM
Reserved
May 15, 2026, 9:46 PM
Status
Awaiting Analysis
Published
Nov 12, 2026, 8:18 PM
Modified
Nov 12, 2026, 10:09 PM