pypdf: Manipulated FlateDecode image dimensions can exhaust RAMGHSA-x284-j5p8-9c5p
MEDIUMFix: py-pdf/pypdf#3734GHSA-x284-j5p8-9c5p is a medium-severity (CVSS 6.5) CWE-789 vulnerability in pypdf. A fix is available for pypdf — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-x284-j5p8-9c5p.
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
pypdfReal-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 the RAM being exhausted. This requires accessing an image using /FlateDecode with large size values.
Patches
This has been fixed in pypdf==6.10.2.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3734.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pypdf | all versions | 6.10.2pip install --upgrade 'pypdf==6.10.2' |
Affected Products
pypdfpy-pdfDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pypdf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pypdf to 6.10.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x284-j5p8-9c5p 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.
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.
To mitigate this issue, avoid processing untrusted PDF files with applications utilizing the pypdf library. Restricting the sources of PDF files to trusted origins can reduce the risk of exploitation.Source: Red Hat security advisory for GHSA-x284-j5p8-9c5p (CC BY 4.0)
Frequently Asked Questions
Is GHSA-x284-j5p8-9c5p in your dependencies?
Find it across PyPI, including transitive dependencies.