---
id: "CVE-2026-119206"
kind: "vulnerability"
aliases: ["CVE-2026-119206"]
title: "pypdf: crafted PDF page labels cause excessive processing time"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["document-processing", "package", "pypdf", "python"]
not_affected_if: ["page-labels-unused", "trusted-input-only"]
published_at: "2026-10-29T21:17:19+00:00"
first_seen_at: "2026-10-29T21:26:51+00:00"
updated_at: "2026-10-29T21:28:38+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119206", "first_seen_at": "2026-10-29T21:26:51+00:00"}]
---

# pypdf: crafted PDF page labels cause excessive processing time

pypdf, a Python library for reading PDF files, can take excessive time to retrieve page labels from a crafted PDF with a flat page-label number tree containing many ranges. An attacker who supplies such a file can tie up a process that parses it, causing slowdown or denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed pypdf version with `pip show pypdf` or `python -c "import pypdf; print(pypdf.__version__)"`.
- Find code that reads the `page_labels` property on untrusted PDF input.

## Fix

- pypdf: upgrade to `6.21.3`.

## Timeline

- 2026-10-29T21:26:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119206

## From the sources

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.3, pypdf can take excessive time to retrieve page labels from a crafted PDF containing a flat page-label number tree with many ranges. The page_labels property resolves each page independently and repeatedly scans the same /Nums array from the beginning, causing work to grow with both the page count and the number of label ranges. This issue is fixed in version 6.21.3.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_