CVE-2026-119205

UNKNOWN 0.0

pypdf: Possible infinite loop when cloning dictionaries

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop when cloning or duplicating a crafted cyclic DictionaryObject. Clone traversal checked generated destination references rather than the original source references, allowing some source cycles to evade the visited-object check. This issue is fixed in version 6.21.4.

CWE	CWE-835
Vendor	py-pdf
Product	pypdf
Published	Oct 29, 2026

Stay Ahead of the Next One

Get instant alerts for py-pdf pypdf

Be the first to know when new unknown vulnerabilities affecting py-pdf pypdf are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

Affected Versions

py-pdf / pypdf

< 6.21.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/py-pdf/pypdf/security/advisories/GHSA-mfr5-77xh-9j7h github.com: https://github.com/py-pdf/pypdf/pull/4288 github.com: https://github.com/py-pdf/pypdf/commit/f176db1a1f7f9af3e472e69a843ef1175653b044 github.com: https://github.com/py-pdf/pypdf/releases/tag/6.21.4