Qt 6.9.0 QtNetwork QHttp2ProtocolHandler use after free

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Qt 6.9.0. The affected element is the function QHttp2ProtocolHandler of the component QtNetwork Module. Performing a manipulation results in use after free. This vulnerability is known as CVE-2025-5991. Attacking locally is a requirement. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Qt 6.9.0. This affects the function QHttp2ProtocolHandler of the component QtNetwork Module. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at codereview.qt-project.org. This vulnerability is uniquely identified as CVE-2025-5991 since 06/11/2025. The exploitability is told to be difficult. An attack has to be approached locally. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 243389 (Linux Distros Unpatched Vulnerability : CVE-2025-5991), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.9.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (243389) and EUVD (EUVD-2025-18092). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔍
CNA CVSS-BT Score: 🔍
CNA Vector: 🔍

CVSSv3info

VulDB Meta Base Score: 4.5
VulDB Meta Temp Score: 4.3

VulDB Base Score: 4.5
VulDB Temp Score: 4.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 243389
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-5991

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Qt 6.9.1

Timelineinfo

06/11/2025 🔍
06/11/2025 +0 days 🔍
06/11/2025 +0 days 🔍
08/06/2025 +55 days 🔍

Sourcesinfo

Advisory: codereview.qt-project.org
Status: Confirmed

CVE: CVE-2025-5991 (🔍)
GCVE (CVE): GCVE-0-2025-5991
GCVE (VulDB): GCVE-100-312285
EUVD: 🔍

Entryinfo

Created: 06/11/2025 09:59
Updated: 08/06/2025 01:24
Changes: 06/11/2025 09:59 (67), 06/11/2025 11:29 (1), 08/06/2025 01:24 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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