pypdf: Possible large memory usage for streams with multiple filtersGHSA-7mh2-4gg2-979f
Fix: py-pdf/pypdf#4173GHSA-7mh2-4gg2-979f is a Uncontrolled Resource Consumption vulnerability in pypdf. A fix is available for pypdf — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
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 large memory consumption. This requires accessing any stream with a large amount of filters or multiple filters which pass around large amounts of data.
Patches
This has been fixed in pypdf==6.20.0.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #4173.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pypdf | all versions | 6.20.0pip install --upgrade 'pypdf==6.20.0' |
Detection & 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 6.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7mh2-4gg2-979f 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 GHSA-7mh2-4gg2-979f in your dependencies?
Find it across PyPI, including transitive dependencies.