# CVE-2026-59924: Mistune: Arbitrary File Read via Include directive path traversal

> Attackers can read arbitrary files outside the intended directory by crafting malicious include paths in Markdown files processed by Mistune.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Jul 2026
- **Updated:** 8 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-59924, ECHO-902c-bf12-91ee, GHSA-r4rv-85jg-w4mf, PYSEC-2026-2212, UBUNTU-CVE-2026-59924

## What is CVE-2026-59924?

CVE-2026-59924 is a medium-severity path traversal vulnerability in lepture mistune, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Include.parse() joins and normalizes user-supplied include paths without verifying that the result remains within the intended markdown directory, allowing crafted include paths to access files outside that directory when markdown files are processed using md.read(). This issue is fixed in version 3.3.0.

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

## Which versions are affected by CVE-2026-59924?

3 open source packages ship an affected version, including mistune. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mistune` | PyPI | All versions | 3.3.0 |
| `mistune` | PyPI | All versions | 3.3.0 |
| `mistune` | PyPI | All versions | 3.3.0 |

Products: Mistune Project Mistune.

## How do I fix CVE-2026-59924?

Upgrade mistune to 3.3.0 or later.

## Is CVE-2026-59924 being exploited?

There is no known exploitation of CVE-2026-59924 in the wild and no public exploit code.

## Other vulnerabilities in lepture mistune

- [CVE-2026-59922](https://insights.sbomify.com/CVE-2026-59922/): Mistune plugins/formatting: quadratic-time parsing on long runs of `~~x~~`, `==x==`, and `^^x^^` markers (strikethrough / mark / insert) (high 7.5)
- [CVE-2026-59925](https://insights.sbomify.com/CVE-2026-59925/): inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs (high 7.5)
- [CVE-2026-59928](https://insights.sbomify.com/CVE-2026-59928/): Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions (high 7.5)
- [CVE-2026-59923](https://insights.sbomify.com/CVE-2026-59923/): Mistune: XSS via percent-encoded javascript URI bypass in safe_url() (medium 6.1)
- [CVE-2026-59929](https://insights.sbomify.com/CVE-2026-59929/): Mistune renderers/html.safe_url: HARMFUL_PROTOCOLS list misses legacy and chained schemes that historically chain to `javascript:` execution (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59924 and fix it if it is affected.

What it is: CVE-2026-59924 is a medium-severity path traversal vulnerability in lepture mistune, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-59924 in the wild and no public exploit code.

Affected packages and fixed versions:
- mistune (PyPI): affected all versions; fixed in 3.3.0
- mistune (PyPI): affected all versions; fixed in 3.3.0
- mistune (PyPI): affected all versions; fixed in 3.3.0

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-2026-59924/ (Markdown: https://insights.sbomify.com/CVE-2026-59924/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59924
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59924
- OSV: https://osv.dev/vulnerability/CVE-2026-59924

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59924/
Summaries are generated and may contain mistakes; the official description above is the record.