LOW3.3
PYSEC-2026-3004
pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams
Quick fix
PYSEC-2026-3004 — pypdf: upgrade to the fixed version with the command below.
pip install --upgrade 'pypdf>=6.12.0'Details
### Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with `/W [0 0 0]` values and large `/Size` values.
### Patches
This has been fixed in [pypdf==6.12.0](https://github.com/py-pdf/pypdf/releases/tag/6.12.0).
### Workarounds
If developers are unable to upgrade their apps immediately, they should consider applying the changes from PR [#3791](https://github.com/py-pdf/pypdf/pull/3791).
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-48156[ADVISORY]
- https://github.com/py-pdf/pypdf/pull/3791[WEB]
- https://github.com/py-pdf/pypdf/commit/507d7c9aa6ea83389b954b9c3c0c528fe5d5da70[WEB]
- https://github.com/py-pdf/pypdf[PACKAGE]
- https://github.com/py-pdf/pypdf/releases/tag/6.12.0[WEB]
- https://pypi.org/project/pypdf[PACKAGE]
- https://github.com/advisories/GHSA-248m-82v9-q6g6[ADVISORY]