CVE-2025-5991

Name: CVE-2025-5991
Creator: NVD / NIST
Published: 2025-06-11T08:15:22.933+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 2.1/10EPSS 0.12%

Last modified Jun 17, 2026

CVE-2025-5991 is a low-severity vulnerability rated 2.1/10 on the CVSS scale. 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. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 4.0

2.1/10

CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.12%

2.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

References

https://codereview.qt-project.org/c/qt/qtbase/+/643777

Timeline

Published: Jun 11, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-5991?

How severe is CVE-2025-5991?

CVE-2025-5991 has a CVSS score of 2.1/10 (LOW severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.

How do I fix CVE-2025-5991?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-5991?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST