Qt Group PlcCVE-2026-76151
qt: out-of-bounds read
Fix: upgrade to 6.8.9 or later (2 fixed versions below)
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| qt Product | >= 6.0.0, < 6.8.9 | 6.8.9 |
| >= 6.9.0, < 6.11.2 | 6.11.2 |