# CVE-2026-16762: Denial-of-service vulnerability in the Qt Core QXmlStream parser (QXmlStreamReader) impacts Qt

CVE-2026-16762 is fixed in qt6-base on 1 platform by DEBIAN-CVE-2026-16762 (version 6.11.2+dfsg-5), released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-16762
- Priority: Routine
- CVSS: n/a (Moderate)
- EPSS: 0.0052
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 23, 2026
- Weakness: Inefficient Algorithmic Complexity
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-16762

## Description

An attacker able to supply a crafted XML document to an application using QXmlStreamReader can cause disproportionate CPU consumption during parsing, making the application unresponsive (denial of service). Exploitation requires only that the application parse attacker-influenced XML; no authentication, privileges, or user interaction beyond ingesting the input are needed. There is no loss of confidentiality or integrity — no data disclosure, data modification, or code execution — and the impact is contained to the affected process.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | qt6-base Debian 14 | 6.11.2+dfsg-5 | [DEBIAN-CVE-2026-16762](https://patchblox.com/security/data/fix/linux/debian-cve-2026-16762.md) | Oct 24, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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