# CVE-2026-47258: BACnet Stack stack-based buffer overflow in Notification Class AddListElement

Source: https://junglewise.ai/threats/cve-2026-47258-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-2026-47258 · Severity: high · CVSS 8.2 · Published 2026-11-12

BACnet Stack is a C library implementing the BACnet protocol used in building automation and control systems. A stack-based buffer overflow in the Notification Class object can be triggered by a remote attacker sending a specially crafted AddListElement request with more recipient-list elements than the system can hold, causing the application to crash or potentially execute arbitrary code.

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-2026-47258 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47258 being exploited in the wild.

**How severe is CVE-2026-47258?** High severity, with a CVSS score of 8.2, published 12 November 2026.

**Which products and versions are affected?** BACnet Stack prior to 1.4.4, 1.5.1, and 1.6.0.

**Is there a fix for CVE-2026-47258?** Yes: fixed in 1.4.4, 1.5.1, 1.6.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47258 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47258?** 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, 1.6.0

## Technical details

A stack-based out-of-bounds write exists in Notification_Class_Add_List_Element() in src/bacnet/basic/object/nc.c when decoding recipient-list elements into a fixed-size stack array (NC_MAX_RECIPIENTS, typically 10 elements). The vulnerable code uses new_element_count as an array index before validating it against the array bounds, allowing an AddListElement request with more than NC_MAX_RECIPIENTS BACNET_DESTINATION elements to overflow the stack buffer. The vulnerability requires notification-class support to be compiled in and the SERVICE_CONFIRMED_ADD_LIST_ELEMENT handler to be registered; exploitation is remote via BACnet protocol.

## Affected products

- BACnet Stack BACnet Stack prior to 1.4.4, 1.5.1, and 1.6.0

## Timeline

- 2026-07-05: disclosed
- 2026-05-18: patched
- 2026-11-12: advisory

## References

- [https://github.com/bacnet-stack/bacnet-stack/pull/1353](https://github.com/bacnet-stack/bacnet-stack/pull/1353)
- [https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-rjmv-3mcm-r83j](https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-rjmv-3mcm-r83j)

## Related threats

- [BACnet Stack buffer overflow in EPICS app](https://junglewise.ai/threats/cve-2026-52786-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for)
- [BACnet Stack stack buffer overflow in life-safety-zone property read](https://junglewise.ai/threats/cve-2026-47711-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for)
- [BACnet Stack stack-based buffer overflow in RemoveListElement](https://junglewise.ai/threats/cve-2026-47259-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for)
- [BACnet Stack restore logic flaw causes data loss](https://junglewise.ai/threats/cve-2026-47257-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for)
- [BACnet Stack uncontrolled recursion in Channel object](https://junglewise.ai/threats/cve-2026-47217-bacnet-stack-is-a-bacnet-open-source-protocol-stack-c-library-for)