CVE-2022-24859 is a medium-severity (CVSS 6.2) vulnerability in pypdf2. 2 public exploit references exist, 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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-24859 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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' |
Research 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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-24859 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-24859. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2022-24859 in your dependencies?
O3 Security finds CVE-2022-24859 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.