---
title: "CVE-2026-76788: Zephyr OSDP Control Panel - Buffer Overflow"
description: "Zephyr OSDP Control Panel (cp_decode_response) contains a stack buffer overflow caused by missing bounds check on payload length in REPLY_KEYPPAD and REPLY_RAW reply types, letting attackers with access to RS-485 bus potentially hijack control flow, exploit requires access to OSDP RS-485 channel and ability to send crafted frames."
url: https://panop.io/threat-heartbeat/CVE-2026-76788/
---

# CVE-2026-76788 Zephyr OSDP Control Panel - Buffer Overflow

Zephyr OSDP Control Panel (cp\_decode\_response) contains a stack buffer overflow caused by missing bounds check on payload length in REPLY\_KEYPPAD and REPLY\_RAW reply types, letting attackers with access to RS-485 bus potentially hijack control flow, exploit requires access to OSDP RS-485 channel and ability to send crafted frames.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-76788)

## Details

Type

Buffer Overflow

Impact

Remote Code Execution

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

19 October 2026

Updated

20 October 2026

Weakness

[CWE-787](https://cwe.mitre.org/data/definitions/787.html)

## Vendor fix

Apply the patch that adds OSDP\_EVENT\_MAX\_DATALEN bounds checks to handlers or update to the latest Zephyr version with this fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-76788](https://nvd.nist.gov/vuln/detail/CVE-2026-76788)
- [https://github.com/zephyrproject-rtos/zephyr/commit/f10d55f47c6970e95d3a7c6ba08e6adec3c79acd](https://github.com/zephyrproject-rtos/zephyr/commit/f10d55f47c6970e95d3a7c6ba08e6adec3c79acd)
- [https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fgg7-h8p9-9q3w](https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fgg7-h8p9-9q3w)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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