CVE-2026-76151: Out-of-bounds read (buffer over-read) vulnerability in HTTP Cache-Control response header parsing impacts Qt Framework (QtNetwork module)
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.
Affected Software
Event History
Frequently Asked Questions
Which applications are exposed to this issue?
Affected applications use QNetworkAccessManager in the QtNetwork module on 64-bit builds and receive HTTP responses from an untrusted or compromised server. Only the client side of an HTTP connection is affected; 32-bit builds are not affected.
What must an attacker do to trigger the vulnerability?
An attacker needs to control, compromise, or otherwise cause the application to connect to an HTTP server that returns an excessively large Cache-Control response header value. Successful exploitation causes an application crash.
Does this issue allow code execution or disclosure of application data?
No. The out-of-bounds access is read-only, and the provided information states that it does not enable information disclosure or code execution.
Which Qt versions are affected?
The affected ranges are Qt 6.0.0 through 6.8.8 and Qt 6.9.0 through 6.11.1.