// For flags

CVE-2025-5991

Use after free in QHttp2ProtocolHandler

Severity Score

2.1
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Attack Requirements
None
Privileges Required
None
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
Low
Low
Integrity
Low
Low
Availability
Low
Low
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-06-11 CVE Reserved
  • 2025-06-11 CVE Published
  • 2025-06-11 CVE Updated
  • 2025-08-18 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-416: Use After Free
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
The Qt Company
Search vendor "The Qt Company"
 Qt
Search vendor "The Qt Company" for product "Qt"
 6.9.0
Search vendor "The Qt Company" for product "Qt" and version "6.9.0"
en
Affected