# CVE-2026-46338: Regression in pymdownx.snippets reintroduces sibling-prefix path traversal bypass despite restrict_base_path

> Attackers can read arbitrary files from sibling directories via path traversal in PyMdown Extensions when restrict_base_path is enabled.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N`)
- **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:** Yes
- **Published:** 16 Jul 2026
- **Updated:** 17 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-46338, GHSA-62q4-447f-wv8h, PYSEC-2026-2999, ROOT-APP-PYPI-CVE-2026-46338, UBUNTU-CVE-2026-46338

## What is CVE-2026-46338?

CVE-2026-46338 is a medium-severity path traversal vulnerability in facelessuser pymdown-extensions, published on 16 Jul 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

PyMdown Extensions is a set of extensions for the Python-Markdown markdown project. From 10.0.1 until 10.21.3, pymdownx.snippets uses a string-prefix containment check in SnippetPreprocessor.get_snippet_path() in pymdownx/snippets.py when `restrict_base_path: True`, allowing markdown snippet directives to read files from sibling paths that share the same base_path prefix, such as docs and docs_internal. This is a regression of CVE-2023-32309. This issue is fixed in version 10.21.3.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-46338?

3 open source packages ship an affected version, including pymdown-extensions. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pymdown-extensions` | PyPI | From 10.0.1 | 10.21.3 |
| `pymdown-extensions` | PyPI | From 10.0.1 | 10.21.3 |
| `pymdown-extensions` | PyPI | From 10.0.1 | 10.21.3 |

Products: Facelessuser Pymdown Extensions.

## How do I fix CVE-2026-46338?

Upgrade pymdown-extensions to 10.21.3 or later.

## Is CVE-2026-46338 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46338 exists.

## Other vulnerabilities in facelessuser pymdown-extensions

- [CVE-2023-32309](https://insights.sbomify.com/CVE-2023-32309/): Arbitrary file inclusion with the pymdowm-snippets extension (high 7.5)
- [CVE-2025-68142](https://insights.sbomify.com/CVE-2025-68142/): PyMdown Extensions has ReDOS bug in Figure Capture extension (low 2.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46338 and fix it if it is affected.

What it is: CVE-2026-46338 is a medium-severity path traversal vulnerability in facelessuser pymdown-extensions, published on 16 Jul 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-2026-46338 exists.

Affected packages and fixed versions:
- pymdown-extensions (PyPI): affected from 10.0.1; fixed in 10.21.3
- pymdown-extensions (PyPI): affected from 10.0.1; fixed in 10.21.3
- pymdown-extensions (PyPI): affected from 10.0.1; fixed in 10.21.3

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-2026-46338/ (Markdown: https://insights.sbomify.com/CVE-2026-46338/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46338
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46338
- OSV: https://osv.dev/vulnerability/CVE-2026-46338

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46338/
Summaries are generated and may contain mistakes; the official description above is the record.