pypdf: Possible large memory usage for streams with multiple filters
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.).
What to do
Upgrade to pypdf version 6.20.0 via https://github.com/py-pdf/pypdf/releases/tag/6.20.0). or apply the changes from PR #4173.).
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | pypdf | < 6.20.0 | 6.20.0 |
References
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-400, CWE-770- Platform
- Python (PyPI)
- Package
pypdf- Disclosed
- 21.10.2026
- Updated
- 22.10.2026 10:00
Sources and licenses · Edited or translated by DockRay; source rights and applicable licenses are retained.
OSV / GitHub Advisory Database - GHSA-7mh2-4gg2-979f - CC BY 4.0
Vulnerability history: pypdf
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 55
- First → latest
- 06.2023 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 10
- Medium 42
- Low 3
Disclosures per year
- 2023: 2
- 2024: 0
- 2025: 4
- 2026: 49
-
pypdf: Possible large memory usage for streams with multiple filters this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.