What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-04-18 · updated 2026-06-17
• Weakness: CWE-835

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.

Affected products

• Debian Linux: 9.0
• Pypdf2 Project Pypdf2: before 1.27.5 — fixed in 1.27.5

How to fix

Upgrade to a fixed version: Pypdf2 Project Pypdf2 1.27.5. Check the vendor advisory for mitigations.

References

• 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://github.com/py-pdf/PyPDF2/security/advisories/GHSA-xcjx-m2pj-8g79
• https://lists.debian.org/debian-lts-announce/2022/06/msg00001.html
• https://lists.debian.org/debian-lts-announce/2023/06/msg00013.html
• 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://github.com/py-pdf/PyPDF2/security/advisories/GHSA-xcjx-m2pj-8g79
• 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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