# CVE-2026-47222: NanaZip: Heap out-of-bounds read in NanaZip AVB property descriptor parser via unsigned integer underflow

> An attacker can cause a denial of service in NanaZip by tricking a user into opening a crafted AVB image file, exploiting an integer underflow.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 12 Jun 2026
- **Updated:** 12 Jun 2026
- **Also known as:** GHSA-mqqj-crf3-6q37

## What is CVE-2026-47222?

CVE-2026-47222 is a medium-severity vulnerability in M2Team NanaZip, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

NanaZip is the 7-Zip derivative intended for the modern Windows experience. From version 3.0.1000.0 to before version 6.0.1698.0, a heap out-of-bounds read exists in the Android Verified Boot (AVB) vbmeta image parser in NanaZip (via the upstream 7-Zip AvbHandler). An unsigned integer underflow in a bounds check allows an attacker-controlled value_num_bytes field to pass validation, causing AddNameToString to read up to ~4 GiB past the end of a 64 KiB heap buffer. This causes a deterministic crash (denial of service) when opening a crafted .avb or .img file. This issue has been patched in stable version 6.0.1698.0 and preview version 6.5.1742.0.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound)), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-47222?


## How do I fix CVE-2026-47222?

No fix has been published for CVE-2026-47222 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47222 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47222 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47222 and fix it if it is affected.

What it is: CVE-2026-47222 is a medium-severity vulnerability in M2Team NanaZip, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47222 exists.

Affected product: M2Team NanaZip. 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-2026-47222/ (Markdown: https://insights.sbomify.com/CVE-2026-47222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47222
- OSV: https://osv.dev/vulnerability/CVE-2026-47222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47222/
Summaries are generated and may contain mistakes; the official description above is the record.