CVE-2023-36464: PYPDF2 Project PYPDF2

Medium severity, CVSS 5.5. EPSS: 0.4% chance of exploitation in the next 30 days.

pypdf is an open source, pure-python PDF library. In affected versions an attacker may craft a PDF which leads to an infinite loop if `__parse_content_stream` is executed. That is, for example, the case if the user extracted text from such a PDF. This issue was introduced in pull request #969 and resolved in pull request #1828. Users are advised to upgrade. Users unable to upgrade may modify the line `while peek not in (b"\r", b"\n")` in `pypdf/generic/_data_structures.py` to `while peek not in (b"\r", b"\n", b"")`.

Affected products

• PYPDF2 Project PYPDF2: from 2.2.0
• Pypdf Project Pypdf: before 3.9.0 (fixed in 3.9.0)

Published 2023-06-27. Last modified 2026-06-17.