Recommended action

Update python-liquid to 2.2.1 if you use the affected versions. Test the change in a non-production environment first.

hol-guard supply-chain scan

What this means

Python Liquid: Infinite loop when parsing malformed `{% case %}` tags affects python-liquid (pip). Severity is high. ### Impact Given a malformed `{% case %}` tag without associated `{% when %}` or `{% else %}` block, and no terminating `{% endcase %}` tag, Python Liquid hangs in an infinite loop at parse time. This allows malicious template authors to craft templates for a denial of service attack. ### Patches The issue is fixed in version 2.2.1 with the correction of the `liquid.TokenStream.eof` attribute. The `kind` and `value` of the special EOF token are now the same, so either can be tested against `liquid.token.TOKEN_EOF`. ### Workarounds Manually correct the definition of `liquid.TokenStream.eof` before parsing any templates. ```python import liquid from liquid.token import TOKEN_EOF liquid.stream.TokenStream.eof = liquid.Token(TOKEN_EOF, TOKEN_EOF, -1, "") # ... ```

AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.

Affected software

Recommended action

Update python-liquid to 2.2.1 if you use the affected versions. Test the change in a non-production environment first.

hol-guard supply-chain scan

What this means

Python Liquid: Infinite loop when parsing malformed `{% case %}` tags affects python-liquid (pip). Severity is high. ### Impact Given a malformed `{% case %}` tag without associated `{% when %}` or `{% else %}` block, and no terminating `{% endcase %}` tag, Python Liquid hangs in an infinite loop at parse time. This allows malicious template authors to craft templates for a denial of service attack. ### Patches The issue is fixed in version 2.2.1 with the correction of the `liquid.TokenStream.eof` attribute. The `kind` and `value` of the special EOF token are now the same, so either can be tested against `liquid.token.TOKEN_EOF`. ### Workarounds Manually correct the definition of `liquid.TokenStream.eof` before parsing any templates. ```python import liquid from liquid.token import TOKEN_EOF liquid.stream.TokenStream.eof = liquid.Token(TOKEN_EOF, TOKEN_EOF, -1, "") # ... ```

AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.

Affected software