Path Traversal in Posit-Dev Py-Shiny
CVE-2026-108258
Shiny for Python is a framework for building interactive web applications in Python. From 1.4.0 until 1.6.4, bookmark restore accepts a client-supplied state_id and joins it into the server-side shiny_bookmarks directory without validating that it is a single safe path segment. An unauthenticated request can use parent-directory segments or an absolute path to make the server open input.json and values.json outside the bookmark store, even when bookmark_store is set to disable. In applications configured with bookmark_store set to server and using ui.input_file(), the restore handler can additionally copy and expose an attacker-selected file from an attacker-selected directory. This issue is fixed in version 1.6.4.
Vulnerability class: Path Traversal (Directory Traversal)
Published .
EPSS exploit prediction
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Affected products
- Posit-Dev Py-Shiny — versions >= 1.4.0, < 1.6.4