CVE-2026-119205

Description

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.

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Weakness Type (CWE)

CWE-835 CWE-835

References

Other References

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

Frequently Asked Questions

What is CVE-2026-119205? +

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.

How do I check if I'm vulnerable to CVE-2026-119205? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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