# CVE-2026-94370: Memory corruption (double free / use-after-free) vulnerability in core string handling impacts Qt for MCUs

> A double free or use-after-free in Qt for MCUs string handling allows attackers to cause memory corruption, potentially leading to code execution or crashes.

- **Severity:** Medium 6.5 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:H/E:U/S:P/AU:N/R:U/V:D/RE:M`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-vcv3-3vwp-2j63

## What is CVE-2026-94370?

CVE-2026-94370 is a medium-severity use after free vulnerability in Qt_for_MCUs, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A defect in the Qt for MCUs core string handling causes heap memory corruption. When an application passes text into Qt Quick Ultralite using the public Qul::String interface type, and that text is held in a std::string, the conversion to the internal string type copies the pointer without taking ownership of it. Two objects then release the same memory, producing a double free, an invalid free, or a use-after-free.

Weakness: CWE-665 (Improper Initialization), CWE-590 (Free of Memory not on the Heap), CWE-416 (Use After Free), CWE-415 (Double Free)

## Which versions are affected by CVE-2026-94370?


## How do I fix CVE-2026-94370?

No fix has been published for CVE-2026-94370 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-94370 being exploited?

There is no known exploitation of CVE-2026-94370 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-94370 and fix it if it is affected.

What it is: CVE-2026-94370 is a medium-severity use after free vulnerability in Qt_for_MCUs, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-94370 in the wild and no public exploit code.

Affected product: Qt_for_MCUs. 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-2026-94370/ (Markdown: https://insights.sbomify.com/CVE-2026-94370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-94370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-94370
- OSV: https://osv.dev/vulnerability/CVE-2026-94370

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-94370/
Summaries are generated and may contain mistakes; the official description above is the record.