CVE-2026-5072
Awaiting Analysis Awaiting Analysis - Queue
Bitwise Shift Vulnerability in Zephyr RTOS PTP Subsystem

Publication date: 2026-05-22

Last updated on: 2026-05-26

Assigner: Zephyr Project

Description
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.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-05-22
Last Modified
2026-05-26
Generated
2026-06-11
AI Q&A
2026-05-22
EPSS Evaluated
2026-06-10
NVD
CVE-2026-5072
EUVD
EUVD-2026-31413
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
zephyrproject zephyr to 4.3 (inc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-20 The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-1335 An integer value is specified to be shifted by a negative amount or an amount greater than or equal to the number of bits contained in the value causing an unexpected or indeterminate result.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Impact Analysis

This vulnerability can lead to a Denial of Service (DoS) condition by causing the system to crash or enter resource starvation loops. Since the vulnerability affects system availability, an attacker can disrupt the normal operation of devices running the Zephyr RTOS by sending crafted PTP messages.

The attack requires no privileges or user interaction and can be executed from an adjacent network, making it relatively easy for an attacker to exploit.

Executive Summary

CVE-2026-5072 is a vulnerability in the Zephyr RTOS Precision Time Protocol (PTP) subsystem caused by improper handling of a bitwise shift operation. A remote attacker can send a specially crafted PTP management message containing a large negative value for log_announce_interval. This negative value is not validated and is used in a bitwise shift operation that exceeds the 64-bit integer width, leading to undefined behavior in C.

This undefined behavior can cause the system to crash due to illegal instruction traps on some architectures or produce incorrect timeout values such as zero, which may lead to resource starvation loops or other logical errors.

Detection Guidance

This vulnerability can be detected by monitoring network traffic for crafted PTP_MSG_MANAGEMENT or Delay Response packets containing unusually large or negative log_announce_interval values. Since the attack involves sending malformed PTP messages with invalid negative intervals, inspecting PTP packets for such anomalies is key.

Specific commands are not provided in the available resources, but network packet capture tools like tcpdump or Wireshark can be used to capture and analyze PTP traffic. For example, using tcpdump to filter PTP packets and then inspecting the log_announce_interval field for invalid values could help detect attempts to exploit this vulnerability.

Mitigation Strategies

Immediate mitigation involves applying patches provided by the Zephyr project that validate the log_announce_interval and log_min_delay_req_interval values against PTP specification limits upon receipt. This prevents the processing of maliciously crafted negative values that trigger the vulnerability.

Additionally, restricting or filtering PTP traffic from untrusted or adjacent networks can reduce exposure, as the attack vector is adjacent and requires no privileges or user interaction.

Compliance Impact

The provided information does not specify any direct impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-5072. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart