Description
A use-after-free vulnerability in the Qt QNetworkAccessManager HTTP/2 client support of the Qt Network module allows a malicious or compromised HTTP/2 server to cause the client application to crash, affecting availability.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| qt | qt | 6.9.0 – < 6.11.3 | 6.11.3 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | qt6-base | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | qt6-base | No fix yet | — |
| Ubuntu 26.04 LTS | qt6-base | No fix yet | — |
| Ubuntu 24.04 LTS | qt6-base | No fix yet | — |
| Ubuntu 22.04 LTS | qt6-base | No fix yet | — |
Advisories 1
- WID-SEC-2026-4137 QT: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Oct 25, 2026