Use-after-free in Qt - CVE-2025-5991
Published: June 30, 2025 / Updated: July 1, 2025
Vulnerability identifier: #VU112058
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-5991
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the QHttp2ProtocolHandler in the QtNetwork module. A remote attacker can trigger a race condition between QHttp2Stream HTTP POST uploads and simultaneous handling of HTTP error responses and perform a denial of service (DoS) attack.
Affected software
Qt
How to mitigate CVE-2025-5991
Install updates from vendor's website.
Qt - update to 6.9.1