Description
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.
Published: 2026-09-16
Score: 4.6 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service via Out-of-Bounds Read
Action: Upgrade
AI Analysis

Impact

An excessive Cache-Control header value sent by an untrusted HTTP server can cause a client-side out‑of‑bounds read in QtNetwork’s header parser. The read is read‑only and does not leak data or allow code execution, but it crashes the application, resulting in a denial of service.

Affected Systems

The Qt Framework (QtNetwork module) version 6.0.0 through 6.8.8 and 6.9.0 through 6.11.1 are vulnerable on 64‑bit builds. The Qt product "qt:qt" is affected; 32‑bit builds are not impacted.

Risk and Exploitability

The CVSS score of 4.6 indicates moderate risk, with an EPSS score below 1% showing that exploitation is unlikely but possible. The vulnerability is not listed in the CISA KEV catalog. Attacks require only that the victim receive a large Cache‑Control header from an HTTP server; no privileged access or special interaction is required. The impact is limited to crashing the client application.

Generated by OpenCVE AI on September 18, 2026 at 09:46 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade to Qt version 6.12 or later, which contains the patch for the header parser.
  • If an upgrade cannot be performed immediately, configure a reverse proxy or firewall to strip or truncate Cache‑Control header values exceeding a safe length before reaching the client application.
  • In application code, add defensive checks that verify the length of Cache‑Control header values before they are processed by QNetworkAccessManager or QtNetwork.

Generated by OpenCVE AI on September 18, 2026 at 09:46 UTC.

Tracking

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Advisories

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History

Wed, 16 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 16 Sep 2026 10:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Out-of-bounds read (buffer over-read) vulnerability in HTTP Cache-Control response header parsing impacts Qt Framework (QtNetwork module)
First Time appeared Qt
Qt qt
Weaknesses CWE-125
CWE-197
CPEs cpe:2.3:a:qt:qt:*:*:*:*:*:*:*:*
Vendors & Products Qt
Qt qt
References
Metrics cvssV4_0

{'score': 4.6, 'vector': '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'}

Subscriptions

Qt Qt
cve-icon MITRE

Status: PUBLISHED

Assigner: Qt

Published:

Updated: 2026-09-16T13:19:40.054Z

Reserved: 2026-08-19T06:21:50.153Z

Link: CVE-2026-76151

cve-icon Vulnrichment

Updated: 2026-09-16T13:19:24.635Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-16T10:16:52.660

Modified: 2026-09-18T19:21:34.307

Link: CVE-2026-76151

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-18T10:00:06Z

Weaknesses