Client-Side Out-of-Bounds Read in BACnet Protocol Stack by BACnet

CVE-2026-46677

What is CVE-2026-46677?

The BACnet Stack, an open-source C library for BACnet protocol in embedded systems, contains a vulnerability prior to versions 1.4.4 and 1.5.1 that leads to a client-side out-of-bounds read. This issue arises from an inconsistency between the returnedRecordCount from a remote responder and the fixed-size fileData[] array. Specifically, the ACK decoding process retains the remote RecordCount while inadequate handling of excess records results in an out-of-bounds access when iterating over fileData. This flaw potentially exposes systems to data leakage risks or crashes, emphasizing the critical importance of upgrading to the patched versions.

References