GHSA-xcjx-m2pj-8g79 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 GHSA-xcjx-m2pj-8g79.
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
GHSA-xcjx-m2pj-8g79 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 379,145 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
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if the PyPDF2 user wrote the following code:
from PyPDF2 import PdfFileReader, PdfFileWriter
from PyPDF2.pdf import ContentStream
reader = PdfFileReader("malicious.pdf", strict=False)
for page in reader.pages:
ContentStream(page.getContents(), reader)
Patches
PyPDF2==1.27.5 and later are patched.
Credits to Sebastian Krause for finding (issue) and fixing (PR) it.
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 GHSA-xcjx-m2pj-8g79 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 GHSA-xcjx-m2pj-8g79 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-xcjx-m2pj-8g79. 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 GHSA-xcjx-m2pj-8g79 in your dependencies?
O3 Security finds GHSA-xcjx-m2pj-8g79 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.