# CVE-2026-55732: Loytec BACnet devices out-of-bounds read in bacdt_datetime_to_tod

Source: https://junglewise.ai/threats/cve-2026-55732-loytec-bacnet-devices-out-of-bounds-read-in-bacdt-datetime-to-tod  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-24. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-55732 · Severity: info · CVSS 8.7 · Published 2026-07-24

Loytec building automation and control devices are vulnerable to a remote attack that can cause them to crash and reboot. By sending a specially crafted network packet, an unauthenticated attacker can disrupt core building services, leading to a denial of service. This affects various automation servers, touch panels, and lighting controllers used in commercial building management.

Technologies: [LOYTEC L-DALI](https://junglewise.ai/threats/technologies/l-dali), [LOYTEC L-GATE](https://junglewise.ai/threats/technologies/l-gate), [LOYTEC L-INX](https://junglewise.ai/threats/technologies/l-inx), [LOYTEC L-IOB](https://junglewise.ai/threats/technologies/l-iob), [LOYTEC L-PAD](https://junglewise.ai/threats/technologies/l-pad), [LOYTEC L-ROC](https://junglewise.ai/threats/technologies/l-roc), [LOYTEC L-VIS](https://junglewise.ai/threats/technologies/l-vis), [LOYTEC LIP-ME201C](https://junglewise.ai/threats/technologies/lip-me201c). Vendors: [LOYTEC](https://junglewise.ai/threats/vendors/loytec).

## Quick answers

**Is CVE-2026-55732 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55732 being exploited in the wild.

**How severe is CVE-2026-55732?** Informational severity, with a CVSS score of 8.7, published 24 July 2026.

**Which products and versions are affected?** LOYTEC L-DALI through 8.4.18; LOYTEC L-GATE through 8.4.18; LOYTEC L-INX through 8.4.18; LOYTEC L-IOB through 8.4.18; and 4 more.

**Is there a fix for CVE-2026-55732?** A patch was published on 2026-07-24: Firmware version 8.4.20 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-55732 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-55732?** Check whether you run LOYTEC L-DALI, LOYTEC L-GATE, LOYTEC L-INX or one of the others listed 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.

## Technical details

An out-of-bounds read vulnerability (CWE-125) exists in the BACnet packet parsing component of multiple Loytec products. The flaw is located in the `bacdt_datetime_to_tod` function, where an invalid month value in a BACnet TimeSynchronization or UTC-TimeSynchronization packet triggers an out-of-bounds read against the `bacdt_days_till_month` lookup table. This causes the `linx_a64.exe` process to crash. Because this process provides core services, repeated crashes lead to a full device reboot. The vulnerability is exploitable over the network without authentication. Firmware version 8.4.20 has been released to mitigate this issue.

## Affected products

- Loytec LIP-ME201C through 8.4.18
- Loytec L-INX through 8.4.18
- Loytec L-GATE through 8.4.18
- Loytec L-ROC through 8.4.18
- Loytec L-IOB through 8.4.18
- Loytec L-DALI through 8.4.18
- Loytec L-VIS through 8.4.18
- Loytec L-PAD through 8.4.18

## Timeline

- 2026-07-24: advisory: NVD and vendor advisory published
- 2026-07-24: patched: Firmware version 8.4.20 released

## References

- [https://www.loytec.com/support/product-security/advisories/8532-dibt-cve-20260608-0001-bacnet-crash-due-to-invalid-timesync-message-high](https://www.loytec.com/support/product-security/advisories/8532-dibt-cve-20260608-0001-bacnet-crash-due-to-invalid-timesync-message-high)

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