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.
The Include directive in
src/mistune/directives/include.pydoes 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:
block_error()in html.py (line 140)render_html_include()(line 72)The Include plugin must be explicitly enabled via the plugins parameter.