# CVE-2026-94029: Apache MINA SSHD: Memory exhaustion in SFTP v6 check-file-name/check-file-handle extension

> Attacker can exhaust server memory via SFTP v6 extension requests, causing denial of service in Apache MINA SSHD.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-94029, GHSA-fj5v-qh2p-6v8f, UBUNTU-CVE-2026-94029

## What is CVE-2026-94029?

CVE-2026-94029 is a medium-severity denial of service vulnerability in Apache MINA SSHD, published on 30 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Server-side memory exhaustion in Apache MINA SSHD 1.0.0 to 2.19.0 and 3.0.0-M1 to 3.0.0-M5, component sshd-sftp, in the SFTP v6 check-file-name/check-file-handle extension. Apache MINA SSHD is a Java library for client-side and server-side SSH.

Using a very small "block size" (for instance 256, which is the minimum) on a huge file generates many (file size / block size) hashes. The resulting SFTP reply message was accumulated fully in memory server-side, which could, with a suitably large (possibly sparse) file exhaust the server-side memory, taking down the server.

Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue by imposing a maximum limit on the size of the reply. Many SFTP implementations have a general limit on the size of SFTP messages anyway; typically 256kB as in OpenSSH or also in Apache MINA SSHD.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-94029?


## How do I fix CVE-2026-94029?

Upgrade to a fixed version.

## Is CVE-2026-94029 being exploited?

There is no known exploitation of CVE-2026-94029 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-94029 and fix it if it is affected.

What it is: CVE-2026-94029 is a medium-severity denial of service vulnerability in Apache MINA SSHD, published on 30 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-94029 in the wild and no public exploit code.

Affected product: Apache MINA SSHD. 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-2026-94029/ (Markdown: https://insights.sbomify.com/CVE-2026-94029/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-94029
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-94029
- OSV: https://osv.dev/vulnerability/CVE-2026-94029

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-94029/
Summaries are generated and may contain mistakes; the official description above is the record.