CVE-2026-16762: CWE-407 Inefficient Algorithmic Complexity in qt
Description
CVE-2026-16762 is a high-severity vulnerability in Qt's QXmlStreamReader component where an attacker can supply a crafted XML document to cause excessive CPU consumption during parsing. This leads to denial of service by making the affected application unresponsive. Exploitation requires only that the application parse attacker-controlled XML input, without any authentication or user interaction. There is no impact on confidentiality or integrity, and no code execution is possible. The vulnerability affects Qt versions from 4.3.0 up to but not including 6.8.9, and from 6.9.0 up to but not including 6.11.2.
CVSS v4.0
Score 8.7high
Affected software
qt
qt
pkg:github/qt/qtbaseRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16762 describes an inefficient algorithmic complexity issue (CWE-407) in Qt's QXmlStreamReader. When parsing specially crafted XML documents, the component consumes disproportionate CPU resources, causing the application to become unresponsive and resulting in denial of service. The vulnerability requires no privileges or user interaction beyond processing attacker-controlled XML input. There is no confidentiality or integrity impact, and no code execution or data modification is possible. Affected versions are Qt >=4.3.0 <6.8.9 and >=6.9.0 <6.11.2. No vendor advisory or patch information is provided, so patch status is not confirmed.
Potential Impact
The vulnerability allows denial of service by causing excessive CPU consumption during XML parsing, making the affected application unresponsive. There is no impact on data confidentiality, integrity, or availability beyond the affected process. No code execution or data disclosure occurs.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, applications should avoid parsing untrusted XML input or implement external controls such as input validation or resource usage limits to mitigate potential denial of service.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Qt
- Date Reserved
- 2026-07-23T14:05:09.271Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6adb25cc4d27ba8daaefef45
Added to database: 10/23/2026, 09:15:56 UTC
Last enriched: 10/23/2026, 09:30:30 UTC
Last updated: 10/23/2026, 09:35:13 UTC
Views: 6
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.