# PSF-2016-9: Issue #26657: HTTP server directory traversal

> An attacker can read arbitrary files on Windows systems using the Python http.server module due to a directory traversal vulnerability.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Mar 2016

## What is PSF-2016-9?

PSF-2016-9 is a path traversal vulnerability, published on 28 Mar 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Fix directory traversal vulnerability with ``http.server`` and
``SimpleHTTPServer`` on Windows.

Regression of Python 3.3.5.

Python issue reported at 2016-03-14.

## Which versions are affected by PSF-2016-9?


## How do I fix PSF-2016-9?

No fix has been published for PSF-2016-9 yet. Limit exposure of the affected software until one is available.

## Is PSF-2016-9 being exploited?

There is no known exploitation of PSF-2016-9 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for PSF-2016-9 and fix it if it is affected.

What it is: PSF-2016-9 is a path traversal vulnerability, published on 28 Mar 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of PSF-2016-9 in the wild and no public exploit code.

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/PSF-2016-9/ (Markdown: https://insights.sbomify.com/PSF-2016-9/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/PSF-2016-9

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From sbomify Insights: https://insights.sbomify.com/PSF-2016-9/
Summaries are generated and may contain mistakes; the official description above is the record.