HIGH8.7
PYSEC-2026-4158
pypdf: Possible large memory usage when retrieving Roman page labels
Quick fix
PYSEC-2026-4158 — pypdf: upgrade to the fixed version with the command below.
pip install --upgrade 'pypdf>=6.17.0'Details
### Impact
An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires accessing the page labels of a document with large Roman numerals.
### Patches
This has been fixed in [pypdf==6.17.0](https://github.com/py-pdf/pypdf/releases/tag/6.17.0).
### Workarounds
If you cannot upgrade yet, consider applying the changes from PR [#4047](https://github.com/py-pdf/pypdf/pull/4047).
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-qv6h-rv94-w285[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-102993[ADVISORY]
- https://github.com/py-pdf/pypdf/pull/4047[WEB]
- https://github.com/py-pdf/pypdf/commit/89db7c4fe9315ecc964bfdf05a4e8c4b94175163[WEB]
- https://github.com/py-pdf/pypdf[PACKAGE]
- https://github.com/py-pdf/pypdf/releases/tag/6.17.0[WEB]
- https://pypi.org/project/pypdf[PACKAGE]
- https://github.com/advisories/GHSA-qv6h-rv94-w285[ADVISORY]