CVE-2026-76151Network attack vector

Client application crash via oversized Cache-Control header

Published Sep 16, 2026 · Updated Sep 16, 2026

Out-of-bounds read in Qt Framework 6.0.0 through 6.8.8 and 6.9.0 through 6.11.1 allows remote attackers to crash client apps. The QtNetwork Cache-Control response parser reads beyond its buffer when QNetworkAccessManager processes an excessively large header value. Exposure requires a 64-bit client application to fetch from an untrusted or compromised HTTP server; the read-only access causes no disclosure or code execution.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Qt Framework 6.0.0 through 6.8.8 and 6.9.0 through 6.11.1 allows remote attackers to crash client apps. The QtNetwork Cache-Control response parser reads beyond its buffer when QNetworkAccessManager processes an excessively large header value. Exposure requires a 64-bit client application to fetch from an untrusted or compromised HTTP server; the read-only access causes no disclosure or code execution.

The record

CVE
CVE-2026-76151
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Qt Company
Product
Qt Framework
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.0.0 <6.8.9
  2. Affected versionversion=6.9.0 <6.11.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Qt Company · Qt Frameworkversion=6.0.0 <6.8.9; version=6.9.0 <6.11.2

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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