Fsspec Filesystem Spec vulnerabilities

1 vulnerability

Known vulnerabilities in Fsspec Filesystem Spec, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.

RoutineCVE-2026-104851fsspec · filesystem_spec +23 morefsspec: Server-Side Template Injection in ReferenceFileSystem leads to Remote Code Executionfsspec is a specification and Python implementation framework for filesystem interfaces. From 0.9.0 until 2026.6.0, fsspec.implementations.reference.ReferenceFileSystem evaluates fields from Kerchunk reference JSON documents through unrestricted jinja2.Template(...).render(...) calls in _process_references1._render_jinja, _process_templates, and _process_gen in fsspec/implementations/reference.py. A document supplied inline or fetched from an attacker-controlled URL can provide template expressions that execute Python code when the reference filesystem is opened, including through consumers such as xarray, before referenced data is read. The _process_gen path is reached whenever a document includes a gen array, while the other paths depend on template-related options and values. This issue is fixed in version 2026.6.0.CVSS8.8HighEPSS0.47%