# CVE-2026-47217: BACnet Stack uncontrolled recursion in Channel object

Source: https://junglewise.ai/threats/cve-2026-47217-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-47217 · Severity: high · CVSS 7.5 · Published 2026-11-12

BACnet Stack is a protocol library used in building automation systems to communicate across networked devices. A remote attacker can crash the default BACnet/IP server by sending specially crafted network packets that trigger unbounded recursion in the Channel object handler, causing a denial-of-service outage. No authentication is required, and the attack is reliable and remotely exploitable.

Technologies: [BACnet Stack](https://junglewise.ai/threats/technologies/bacnet-stack-bacnet-stack). Vendors: [BACnet Stack](https://junglewise.ai/threats/vendors/bacnet-stack).

## Quick answers

**Is CVE-2026-47217 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47217 being exploited in the wild.

**How severe is CVE-2026-47217?** High severity, with a CVSS score of 7.5, published 12 November 2026.

**Which products and versions are affected?** BACnet Stack <=1.5.0; fixed in 1.4.4 and 1.5.1.

**Is there a fix for CVE-2026-47217?** 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-2026-47217 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-47217?** 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 stack overflow vulnerability exists in the Channel object's write path due to missing cycle detection in self-referential member lists. An attacker can persist a PROP_LIST_OF_OBJECT_PROPERTY_REFERENCES entry pointing back to the same Channel's PROP_PRESENT_VALUE; a subsequent WriteProperty request triggers recursive re-entry through Channel_Write_Property → Channel_Present_Value_Write → Channel_Write_Members → Device_Write_Property, exhausting stack space. The vulnerability requires network access to the BACnet/IP server and no prior authentication.

## Affected products

- bacnet-stack BACnet Stack <=1.5.0; fixed in 1.4.4 and 1.5.1

## Timeline

- 2026-07-05: disclosed
- 2026-05-13: patched

## References

- [https://github.com/bacnet-stack/bacnet-stack/pull/1345](https://github.com/bacnet-stack/bacnet-stack/pull/1345)
- [https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-wjw5-q9g6-2764](https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-wjw5-q9g6-2764)

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