GHSA-h7ww-273w-6cm8
Mistune: Path Traversal and XSS in Include directive
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
The Include directive in `src/mistune/directives/include.py` does not validate that the resolved file path stays within the source directory, allowing path traversal via `../` sequences to read arbitrary files.
Additionally, error messages and included file contents are rendered without HTML escaping, leading to XSS even when `escape=True`.
Affected functions:
- Path resolution (lines 27-31)
- `block_error()` in html.py (line 140)
- `render_html_include()` (line 72)
The Include plugin must be explicitly enabled via the plugins parameter.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/lepture/mistune/security/advisories/GHSA-h7ww-273w-6cm8
- https://nvd.nist.gov/vuln/detail/CVE-2026-115355
- https://github.com/lepture/mistune/commit/1bef343ade163fc3bb95572b15be720084cdb993
- https://github.com/lepture/mistune
- https://github.com/lepture/mistune/releases/tag/v3.3.0
- https://www.vulncheck.com/advisories/mistune-before-3.3.0-path-traversal-and-xss-via-include-directive