### Impact
An attacker who uses this vulnerability can craft a PDF which leads to large memory usage and/or long runtimes. This requires retrieving the form fields of a document.
### Patches
This has been fixed in [pypdf==6.21.0](https://github.com/py-pdf/pypdf/releases/tag/6.21.0).
### Workarounds
If you cannot upgrade yet, consider applying the changes from PR [#4219](https://github.com/py-pdf/pypdf/pull/4219).