---
id: "CVE-2026-101201"
kind: "vulnerability"
aliases: ["CVE-2026-101201"]
title: "Qt: malformed binary JSON header causes out-of-bounds read"
severity: "medium"
cvss: 4.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c++", "desktop-apps", "package", "qt"]
not_affected_if: ["no-untrusted-binary-json"]
published_at: "2026-10-20T09:17:08+00:00"
first_seen_at: "2026-10-23T21:57:20+00:00"
updated_at: "2026-10-25T04:39:26+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101201", "first_seen_at": "2026-10-23T21:57:20+00:00"}]
---

# Qt: malformed binary JSON header causes out-of-bounds read

A malformed header in binary data passed to QBinaryJson::fromBinaryData() in Qt triggers an out-of-bounds read, which is undefined behaviour. The sources do not say whether this leads to code execution or only a crash or information leak.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-101201

## From the sources

A malformed header in the binary file fed to QBinaryJson::fromBinaryData() can cause undefined behaviour because of out-of-bounds read.

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