vulnerability / NVI-00016147 / Revision 1
Mistune: Arbitrary File Read via Include directive path traversal
GitHub lists this reviewed advisory for mistune. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.9 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
mistune
source listed< 3.3.0
### Summary A path traversal issue exists in mistune's `Include` directive when markdown files are processed using `md.read()`. A crafted include path can cause files outside the intended markdown directory to be accessed. ### Details The issue occurs in the `Include.parse()` method where user-supplied paths are joined and normalized without verifying that the resulting path remains within an expected directory. ```python relpath = self.parse_title(m) dest = os.path.join(os.path.dirname(source_file), relpath) dest = os.path.normpath(dest) ``` Because the final path is not restricted to a trusted base directory, path traversal sequences such as `../` may reference files outside the intended location. ### Proof of Concept Create a markdown file: ```markdown .. include:: ../../../example.txt ``` Process it using: ```python import mistune from mistune.directives import RSTDirective, Include md = mistune.create_markdown( plugins=[RSTDirective([Include()])] ) result, state = md.read("test.md") print(result) ``` ### Impact Applications that process untrusted markdown files with the `Include` directive enabled may allow unintended file access. The impact depends on how th
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-r4rv-85jg-w4mf ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.