# CVE-2026-27711: NanaZip UFS Archive Parser Memory Corruption via Unvalidated Directory Record Length

> A crafted UFS archive file can trigger memory corruption in NanaZip, potentially allowing code execution or crashing the application.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-rjwv-4w7x-hc9c

## What is CVE-2026-27711?

CVE-2026-27711 is a medium-severity memory corruption vulnerability in M2Team NanaZip, published on 25 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

NanaZip is an open source file archive. Starting in version 5.0.1252.0 and prior to versions 6.0.1638.0 and 6.5.1638.0, a memory corruption vulnerability in NanaZip’s UFS parser allows a crafted `.ufs/.ufs2/.img` file to trigger out-of-bounds memory access during archive open/listing. The bug is reachable via normal user file-open flow and can cause process crash, hang, and potentially exploitable heap corruption. Versions 6.0.1638.0 and 6.5.1638.0 fix the issue.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-27711?

It affects 1 product.


Products: M2team Nanazip.

## How do I fix CVE-2026-27711?

No fix has been published for CVE-2026-27711 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27711 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27711 exists.

## Other vulnerabilities in M2Team NanaZip

- [CVE-2026-26282](https://insights.sbomify.com/CVE-2026-26282/): NanaZip has DotNet Single file OOB Heap Read (medium 5.2)
- [CVE-2026-27709](https://insights.sbomify.com/CVE-2026-27709/): NanaZip .NET Single-File Manifest Parser Vulnerable to Out-of-Bounds Read via Unchecked RelativePathLength (medium 5.1)
- [CVE-2026-27710](https://insights.sbomify.com/CVE-2026-27710/): NanaZip .NET Single-File Parser Integer Underflow Leads to Unbounded Allocation (DoS) (medium 5.1)
- [CVE-2026-27014](https://insights.sbomify.com/CVE-2026-27014/): NanZip has ROMFS Archive Infinite Loop / Stack Overflow (medium 5.1)
- [CVE-2026-27114](https://insights.sbomify.com/CVE-2026-27114/): NanaZip has ROMFS Archive Infinite Loop (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27711 and fix it if it is affected.

What it is: CVE-2026-27711 is a medium-severity memory corruption vulnerability in M2Team NanaZip, published on 25 Feb 2026. It can only be exploited from the same machine or local network, 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-2026-27711 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-2026-27711/ (Markdown: https://insights.sbomify.com/CVE-2026-27711/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27711
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27711
- OSV: https://osv.dev/vulnerability/CVE-2026-27711

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27711/
Summaries are generated and may contain mistakes; the official description above is the record.