# CVE-2023-36810: pypdf2: pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files

CVE-2023-36810 is fixed in 3 products on 1 platform, first by python-pypdf2 1.26.0-2ubuntu0.1~esm2, released June 30, 2023. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-36810
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0063
- 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. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions from 1.27.9 include this fix. Users are advised to upgrade. There are no known workarounds for this vulnerability.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pypdf2 Debian 12.15 (bookworm) | 1.27.9-1 | [DEBIAN-CVE-2023-36810](https://patchblox.com/security/data/fix/linux/debian-cve-2023-36810.md) | Jun 30, 2023 |
| Linux | python-pypdf2 Ubuntu 18.04.6 LTS (bionic) | 1.26.0-2ubuntu0.1~esm2 | [python-pypdf2 1.26.0-2ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-pypdf2-1.26.0-2ubuntu0.1-esm2.md) | Jun 30, 2023 |
| Linux | python-pypdf2 Ubuntu 20.04 LTS (focal) | 1.26.0-3ubuntu1.20.04.2 | [python-pypdf2 1.26.0-3ubuntu1.20.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python-pypdf2-1.26.0-3ubuntu1.20.04.2.md) | Jun 30, 2023 |
| Linux | python3-pypdf2 Ubuntu 18.04.6 LTS (bionic) | 1.26.0-2ubuntu0.1~esm2 | [python3-pypdf2 1.26.0-2ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-pypdf2-1.26.0-2ubuntu0.1-esm2.md) | Jun 30, 2023 |
| Linux | python3-pypdf2 Ubuntu 20.04 LTS (focal) | 1.26.0-3ubuntu1.20.04.2 | [python3-pypdf2 1.26.0-3ubuntu1.20.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-pypdf2-1.26.0-3ubuntu1.20.04.2.md) | Jun 30, 2023 |
| Linux | python3-pypdf2 Ubuntu 22.04.1 LTS (jammy) | 1.26.0-4ubuntu0.22.04.2 | [python3-pypdf2 1.26.0-4ubuntu0.22.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-pypdf2-1.26.0-4ubuntu0.22.04.2.md) | Jun 30, 2023 |

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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

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