---
id: CVE-2026-103653
title: Out-of-bounds read vulnerability in CoAP message parsing impacts Qt CoAP
summary: "An out-of-bounds read vulnerability in the Qt CoAP message parsing (QCoapInternalReply::createFromFrame()) of the Qt CoAP module.\_Processing a malformed CoAP message can cause an application using Qt CoAP to crash (loss of availability) …"
severity: medium
cvss: 6.7
cvssVector: >-
  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:U/AU:Y/R:U/RE:L/U:Amber
cvssSource: cna
cwe:
  - CWE-125
vendor: qt
product: Qt
affected:
  - Qt >= 5.13.0 <= 6.8.8
  - Qt >= 6.9.0 <= 6.11.2
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-11-03T20:06:32.421773Z'
published: '2026-11-03'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T20:06:47.825Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-103653'
references:
  - url: >-
      https://wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products#CVE-2026-103653:
  - url: 'https://codereview.qt-project.org/c/qt/qtcoap/+/760652'
  - url: 'https://codereview.qt-project.org/c/qt/qtcoap/+/761120'
tags:
  - cve.org
epss: 0.00291
epssPercentile: 0.21847
ingestedAt: '2026-11-05T20:33:06.430Z'
---

## Overview

An out-of-bounds read vulnerability in the Qt CoAP message parsing (QCoapInternalReply::createFromFrame()) of the Qt CoAP module. Processing a malformed CoAP message can cause an application using Qt CoAP to crash (loss of availability) or to continue operating on incorrect data (potential loss of integrity).

## Affected

- `Qt >= 5.13.0 <= 6.8.8`
- `Qt >= 6.9.0 <= 6.11.2`

## Remediation

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