# CVE-2026-47257: BACnet Stack restore logic flaw causes data loss

Source: https://junglewise.ai/threats/cve-2026-47257-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-2026-47257 · Severity: high · CVSS 8.1 · Published 2026-11-12

BACnet Stack is a protocol library used in embedded building automation systems. When backup/restore is enabled, an authenticated attacker can trigger a restore operation that deletes all existing device objects without actually restoring any data, causing permanent configuration loss while falsely reporting success to the client.

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-2026-47257 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47257 being exploited in the wild.

**How severe is CVE-2026-47257?** High severity, with a CVSS score of 8.1, published 12 November 2026.

**Which products and versions are affected?** BACnet Stack 1.5.0, 1.6.0-rc1.

**Is there a fix for CVE-2026-47257?** Yes: fixed in 1.5.1, 1.6.0. Until then: Disable BACNET_BACKUP_RESTORE unless backup/restore functionality is required, or implement strict access controls to restrict which principals can invoke the ReinitializeDevice service. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47257 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47257?** 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 1.5.1, 1.6.0

Disable BACNET_BACKUP_RESTORE unless backup/restore functionality is required, or implement strict access controls to restrict which principals can invoke the ReinitializeDevice service.

## Technical details

A logic flaw in Device_End_Restore() deletes existing objects before validating the restore source is non-empty and decodable. When the restore file is empty or corrupt, no objects are recreated but the operation still returns success (IDLE state), causing destructive data loss. The vulnerability requires BACNET_BACKUP_RESTORE to be enabled and authentication to invoke ReinitializeDevice.

## Affected products

- BACnet Stack BACnet Stack 1.5.0, 1.6.0-rc1

## Timeline

- 2026-11-12: disclosed
- 2026-05-18: patched: Fix merged in PR #1352
- 2026-07-05: other: GHSA advisory published

## References

- [https://github.com/bacnet-stack/bacnet-stack/pull/1352](https://github.com/bacnet-stack/bacnet-stack/pull/1352)
- [https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-x6pp-3pf3-f87r](https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-x6pp-3pf3-f87r)

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