---
id: CVE-2026-5072
title: >-
  A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote
  attacker to cause undefined behavior and potential system crashes
summary: >-
  A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote
  attacker to cause undefined behavior and potential system crashes. An attacker
  sends a crafted PTP_MSG_MANAGEMENT message to set an unvalidated negative
  log_announce…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1335
vendor: zephyrproject
product: zephyr
affected:
  - zephyr <= 4.3.0
published: '2026-05-22'
updated: '2026-07-08'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-5072'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3v98-458v-388r
    label: vulnerabilities@zephyrproject.org
tags:
  - nvd
epss: 0.003
epssPercentile: 0.22946
ingestedAt: '2026-07-08T13:51:10.764Z'
---

## Overview

A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote attacker to cause undefined behavior and potential system crashes. An attacker sends a crafted PTP_MSG_MANAGEMENT message to set an unvalidated negative log_announce_interval value in the port's data set. When a subsequent PTP_MSG_ANNOUNCE message is processed, port_timer_set_timeout_random computes a timeout as NSEC_PER_SEC >> -log_seconds; if the attacker-supplied value is sufficiently negative (e.g., -127), the shift amount exceeds the 64-bit integer width, triggering undefined behavior in C. This can cause a system crash via a compiler-generated illegal instruction trap on some architectures, or produce an erroneous zero timeout leading to resource starvation loops or other logical errors.

## Affected

- `zephyr <= 4.3.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.