Description
There is a "Use After Free" vulnerability in Qt's QHttp2ProtocolHandler in the QtNetwork module. This only affects HTTP/2 handling, HTTP handling is not affected by this at all. This happens due to a race condition between how QHttp2Stream uploads the body of a
POST request and the simultaneous handling of HTTP error responses.
This issue only affects Qt 6.9.0 and has been fixed for Qt 6.9.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Qt | Qt | 6.9.0 | 6.9.1 |
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | qt6-base +1 | No fix yet | — |
| Ubuntu 26.04 LTS | qt6-base +1 | No fix yet | — |
| Ubuntu 25.10 | qt6-base +1 | No fix yet | — |
| Ubuntu 24.04 LTS | qt6-base +1 | No fix yet | — |
| Ubuntu 22.04 LTS | qt6-base +1 | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | qtbase-opensource-src-gles | No fix yet | — |
| Ubuntu 16.04 LTS | qtbase-opensource-src-gles | No fix yet | — |
Advisories 1
- WID-SEC-2025-1311 QT: Schwachstelle ermöglicht nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jun 11, 2025