An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.
That is, for example, the case when the pypdf-user manipulates an incoming malicious PDF e.g. by merging it with another PDF or by adding annotations.
The issue was fixed with #2264
If you cannot update your version of pypdf, you should modify pypdf/generic/_data_structures.py
just like #2264 did.
{ "nvd_published_at": "2023-10-31T16:15:09Z", "cwe_ids": [ "CWE-835" ], "severity": "MODERATE", "github_reviewed": true, "github_reviewed_at": "2023-10-31T22:22:50Z" }