# RUSTSEC-2026-0271: FTP command injection via CRLF in control channel arguments

> Attackers can inject arbitrary FTP commands via CRLF in untrusted input, leading to unauthorized file deletion or data redirection.

- **Severity:** Not scored
- **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:** 18 Aug 2026
- **Also known as:** GHSA-8mhj-xm4h-m5m6

## What is RUSTSEC-2026-0271?

RUSTSEC-2026-0271 is a command injection vulnerability in suppaftp, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Affected versions of `suppaftp` wrote command arguments (user name, password, paths, `SITE` arguments and custom commands) to the FTP control channel without validation. An argument containing a carriage return (`\r`) or a line feed (`\n`) terminated the intended command line and let a second, attacker-chosen command be sent to the server within the same authenticated session.

An application that passes untrusted input as credentials, paths or command strings to methods such as `login`, `cwd`, `mkdir`, `rmdir`, `rm`, `rename`, `retr`, `put_file`, `site` or `custom_command` can therefore be made to execute arbitrary FTP commands with the application's privileges, for example deleting files or redirecting a data connection with an injected `PORT`.

All three clients are affected: sync, tokio and smol, with or without TLS.

The flaw was corrected in version 10.0.2 (commit [194bdd1](https://github.com/veeso/suppaftp/commit/194bdd1979b16c4848d1fad6897dfa524b688d88)): every command line is validated before it is written to the wire and rejected with `FtpError::ConnectionError` (`std::io::ErrorKind::InvalidInput`) if it contains CR or LF anywhere but in the trailing terminator. As a consequence, `custom_command` no longer accepts several commands joined by CRLF in a single call.

Users who cannot upgrade should reject or strip `\r` and `\n` from any untrusted string before passing it to the client.

## Which versions are affected by RUSTSEC-2026-0271?

1 open source package ship an affected version, including suppaftp.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `suppaftp` | crates.io | From 0.0.0-0 | 10.0.2 |

## How do I fix RUSTSEC-2026-0271?

Upgrade suppaftp to 10.0.2 or later.

## Is RUSTSEC-2026-0271 being exploited?

There is no known exploitation of RUSTSEC-2026-0271 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0271 and fix it if it is affected.

What it is: RUSTSEC-2026-0271 is a command injection vulnerability in suppaftp, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of RUSTSEC-2026-0271 in the wild and no public exploit code.

Affected packages and fixed versions:
- suppaftp (crates.io): affected from 0.0.0-0; fixed in 10.0.2

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/RUSTSEC-2026-0271/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0271/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0271

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0271/
Summaries are generated and may contain mistakes; the official description above is the record.