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


- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/S:P/AU:Y/R:A/RE:L`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** AZL-111425, DEBIAN-CVE-2026-16762, ECHO-9e96-ce4f-470a, GHSA-3gxv-qxph-7hg3, UBUNTU-CVE-2026-16762

## What is CVE-2026-16762?

CVE-2026-16762 is a high-severity vulnerability in qt, published on 23 Oct 2026. 

### Official 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.

Weakness: CWE-407 (Inefficient Algorithmic Complexity)

## Which versions are affected by CVE-2026-16762?


## How do I fix CVE-2026-16762?

Upgrade to a fixed version.

## Is CVE-2026-16762 being exploited?

There is no known exploitation of CVE-2026-16762 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16762 and fix it if it is affected.

What it is: CVE-2026-16762 is a high-severity vulnerability in qt, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-16762 in the wild and no public exploit code.

Affected product: qt. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-16762/ (Markdown: https://insights.sbomify.com/CVE-2026-16762/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16762
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16762
- OSV: https://osv.dev/vulnerability/CVE-2026-16762

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16762/
Summaries are generated and may contain mistakes; the official description above is the record.