---
id: CVE-2026-13481
title: Out-of-bounds read in PTP management TLV TIME parsing in Zephyr net PTP
summary: >-
  The IEEE 1588 PTP management-message parser in subsys/net/lib/ptp/tlv.c
  mishandles the PTP_MGMT_TIME management id. In tlv_mgmt_post_recv(), the
  PTP_MGMT_TIME case casts mgmt_tlv->data to a 10-byte struct ptp_timestamp and
  reads it (then…
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-125
vendor: zephyrproject
product: zephyr
affected:
  - zephyr >= 3.7.0 < 4.3.2
  - zephyr >= 4.4.0 < 4.4.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-26T15:45:34.258604Z'
published: '2026-08-26'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T05:00:00.971Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-13481'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/commit/de98c3721a0e21ca269313997736f4f6193909ef
    label: Fix commit
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-mh5r-jxh8-hxwx
    label: GHSA-mh5r-jxh8-hxwx
tags:
  - cve.org
epss: 0.00244
epssPercentile: 0.15769
ingestedAt: '2026-11-05T20:33:06.708Z'
---

## Overview

The IEEE 1588 PTP management-message parser in subsys/net/lib/ptp/tlv.c mishandles the PTP_MGMT_TIME management id. In tlv_mgmt_post_recv(), the PTP_MGMT_TIME case casts mgmt_tlv->data to a 10-byte struct ptp_timestamp and reads it (then byte-swaps and writes it back) without first checking that the TLV data field is at least sizeof(struct ptp_timestamp). Every sibling management id in the same switch validates its length first; PTP_MGMT_TIME was the only case lacking that check.

The length passed in is the management data size (tlv->length - 2), and the upstream guard in ptp_tlv_post_recv() only requires tlv->length > 2, while msg_tlv_post_recv() validates only that the TLV fits within the received byte count, not a per-id minimum. A peer on the local PTP segment can therefore send a PTP_MSG_MANAGEMENT message carrying a short PTP_MGMT_TIME TLV (data as small as 2 bytes), causing the parser to read and write 8 bytes beyond the validated data. The message type and TLV contents are taken straight off the wire, so the path is reachable by any adjacent attacker when CONFIG_PTP is enabled.

The over-read and write-back stay within the struct ptp_msg allocation (mgmt_tlv->data lives in the leading mtu[NET_ETH_MTU] union member, so data + 10 lands at most a few bytes past mtu[], inside the same object), so this is an out-of-bounds read of adjacent in-object memory plus a bounded in-place corruption of the message's parsed timestamp, not past-allocation memory corruption. Impact is limited to minor information exposure of adjacent bytes and corruption of the device's parsed management TIME value; there is no crash on the access and no reachable reference-count corruption.

The fix adds if (length < sizeof(struct ptp_timestamp)) { return -EBADMSG; } before the cast, matching the other management-id cases and fully closing the receive-path defect.

## Affected

- `zephyr >= 3.7.0 < 4.3.2`
- `zephyr >= 4.4.0 < 4.4.2`

## Remediation

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