---
id: CVE-2026-76151
title: >-
  Out-of-bounds read (buffer over-read) in the HTTP Cache-Control response
  header parsing in the QtNetwork module in Qt Group Qt 6.0.0 through 6.8.8, and
  6.9.0 through 6.11.1, allows remote attackers to cause a denial of service
  (applicati…
summary: >-
  Out-of-bounds read (buffer over-read) in the HTTP Cache-Control response
  header parsing in the QtNetwork module in Qt Group Qt 6.0.0 through 6.8.8, and
  6.9.0 through 6.11.1, allows remote attackers to cause a denial of service
  (applicati…
severity: medium
cvss: 4.6
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/AU:N/R:A'
cwe:
  - CWE-125
  - CWE-197
vendor: qt
product: qt
affected:
  - qt >= 6.0.0 < 6.8.9
  - qt >= 6.9.0 < 6.11.2
published: '2026-09-16'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:21:34.307'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76151'
references:
  - url: 'https://codereview.qt-project.org/c/qt/qtbase/+/752129'
    label: a59d8014-47c4-4630-ab43-e1b13cbe58e3
tags:
  - nvd
  - cve.org
epss: 0.00642
epssPercentile: 0.49418
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T13:19:18.218493Z'
cvssSource: cna
ingestedAt: '2026-09-16T10:53:53.922Z'
---

## Overview

Out-of-bounds read (buffer over-read) in the HTTP Cache-Control response header parsing in the QtNetwork module in Qt Group Qt 6.0.0 through 6.8.8, and 6.9.0 through 6.11.1, allows remote attackers to cause a denial of service (application crash) via an excessively large Cache-Control header value returned by an untrusted or compromised HTTP server to an application using QNetworkAccessManager. Only the client side of the connection is affected and 32-bit builds are not affected; the out-of-bounds access is read-only, with no information disclosure and no code execution.

## Remediation

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