Low severity · published Jun 11, 2025
CVE-2025-5991
Use after free in QHttp2ProtocolHandler
2.1
CVSS
0.1%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
QT
Qt · Qt
6.9.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-5991
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-5991
codereview.qt-project.org
https://codereview.qt-project.org/c/qt/qtbase/+/643777
security-tracker.debian.org
https://security-tracker.debian.org/tracker/CVE-2025-5991
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