Is CVE-2026-46677 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-46677 being exploited in the wild.

How severe is CVE-2026-46677?

Medium severity, with a CVSS score of 6.5, published 12 November 2026.

Which products and versions are affected?

BACnet Stack prior to 1.4.4 and 1.5.1.

Is there a fix for CVE-2026-46677?

Yes: fixed in 1.4.4, 1.5.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-46677 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-46677?

Check whether you run BACnet Stack at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-46677: BACnet Stack out-of-bounds read in AtomicReadFile-ACK

CVE-2026-46677 · Severity: medium · CVSS 6.5 · Published 2026-11-12

BACnet Stack is a C library implementing the BACnet protocol, widely used in building automation and HVAC systems. A remote attacker can send a crafted network message that causes the library to read beyond allocated memory, potentially exposing sensitive data or crashing devices that process BACnet file transfer requests.

Technologies: BACnet Stack. Vendors: BACnet Stack.

Quick answers

Is CVE-2026-46677 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-46677 being exploited in the wild.
How severe is CVE-2026-46677?: Medium severity, with a CVSS score of 6.5, published 12 November 2026.
Which products and versions are affected?: BACnet Stack prior to 1.4.4 and 1.5.1.
Is there a fix for CVE-2026-46677?: Yes: fixed in 1.4.4, 1.5.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-46677 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-46677?: Check whether you run BACnet Stack at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 1.4.4, 1.5.1

Technical details

A client-side stack out-of-bounds read occurs in the AtomicReadFile-ACK decoder when the remote returnedRecordCount exceeds the fixed BACNET_READ_FILE_RECORD_COUNT array capacity. The decode path preserves the oversized count without truncation, and downstream code iterates over this count while accessing the undersized fileData[] array without bounds checking. An unauthenticated remote attacker can trigger this by sending an AtomicReadFile ACK message with RecordCount greater than the local array size.

Affected products

BACnet Stack BACnet Stack prior to 1.4.4 and 1.5.1

Timeline

2026-11-12: disclosed: CVE-2026-46677 published
2026-05-13: patched: Fix merged in PR #1344

References

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