CVE-2025-5991
LowCVSS 2.1Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A Use-After-Free vulnerability in Qt's QHttp2ProtocolHandler in the QtNetwork module affects only HTTP/2 handling. It arises from a race condition between uploading POST request body and simultaneous handling of HTTP errors. Affects only Qt 6.9.0; fixed in Qt 6.9.1.
Risk Assessment
The organization risks application crashes using HTTP/2 in Qt, potentially leading to network service disruptions.
Recommendation
Update Qt to version 6.9.1 to eliminate the Use-After-Free vulnerability in HTTP/2 handling.
Original NVD description (English source)
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.