CVE-2022-24859 is a medium-severity (CVSS 6.2) CWE-835 vulnerability in pypdf2. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for pypdf2 — see the affected versions and patch details below.
Manipulated inline images can cause Infinite Loop in PyPDF2
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-24859.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
pypdf2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pypdf2 | all versions | 1.27.5pip install --upgrade 'pypdf2==1.27.5' |
Affected Products
debian linuxdebianpypdf2pypdf2_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pypdf2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pypdf2 to 1.27.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-24859 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2022-24859 in your dependencies?
Find it across PyPI, including transitive dependencies.