CVE-2026-84309

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.

References

• https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b
• https://github.com/py-pdf/pypdf/pull/3964
• https://github.com/py-pdf/pypdf/releases/tag/6.16.0
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg