# CVE-2023-36807: pypdf2: pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files

CVE-2023-36807 is fixed in pypdf2 on 1 platform by DEBIAN-CVE-2023-36807 (version 2.10.7-1), released June 30, 2023. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-36807
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0057
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 30, 2023

## Description

pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. In version 2.10.5 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 if the user extracted metadata from such a malformed PDF. Versions prior to 2.10.5 throw an error, but do not hang forever. This issue was fixed with https://github.com/py-pdf/pypdf/pull/1331 which has been included in release 2.10.6. Users are advised to upgrade. Users unable to upgrade should modify `PyPDF2/generic/_data_structures.py::read_object` to an an error throwing case. See GHSA-hm9v-vj3r-r55m for details.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pypdf2 Debian 12.15 (bookworm) | 2.10.7-1 | [DEBIAN-CVE-2023-36807](https://patchblox.com/security/data/fix/linux/debian-cve-2023-36807.md) | Jun 30, 2023 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.