# CVE-2026-16762: Qt QXmlStreamReader denial of service via crafted XML

Source: https://junglewise.ai/threats/cve-2026-16762-an-attacker-able-to-supply-a-crafted-xml-document-to-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-23. Updated: 2026-10-23  
License: CC BY 4.0 with a link back

CVE-2026-16762 · Severity: info · Published 2026-10-23

Qt's QXmlStreamReader component, used by many applications to parse XML files, can be made to consume excessive CPU resources when processing a malicious XML document, causing the application to become unresponsive. An attacker needs only to supply a crafted XML file to an application that uses this component; no authentication or special access is required. The impact is limited to denial of service with no data theft or system compromise.

Technologies: [Qt](https://junglewise.ai/threats/technologies/qt-qt). Vendors: [Qt](https://junglewise.ai/threats/vendors/qt).

## Quick answers

**Is CVE-2026-16762 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-16762 being exploited in the wild.

**How severe is CVE-2026-16762?** Informational severity, published 23 October 2026.

**Which products and versions are affected?** Qt <unknown.

**Is there a fix for CVE-2026-16762?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-16762 attacked?** It is attacked over the network or with local access, in a software library.

**Am I affected by CVE-2026-16762?** Check whether you run Qt at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

QXmlStreamReader exhibits a denial-of-service vulnerability where specially crafted XML documents trigger disproportionate CPU consumption during parsing. The attack requires only network or local ability to supply malicious XML input to an application using the affected component; no authentication or user interaction beyond parsing the input is necessary. An attacker gains temporary denial of service against the affected application process, with no code execution or data exposure.

## Affected products

- Qt Qt <unknown

## Timeline

- 2026-10-23: disclosed

## References

- [https://codereview.qt-project.org/c/qt/qtbase/+/738885](https://codereview.qt-project.org/c/qt/qtbase/+/738885)
- [https://codereview.qt-project.org/c/qt/qtbase/+/738901](https://codereview.qt-project.org/c/qt/qtbase/+/738901)

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