medium5.5
CVE-2026-84309
pypdf: Possible infinite loop for TreeObject.insert_child
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.16.0 | 6.16.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.16.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-jp53-mhqp-8xcg
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg
- https://github.com/py-pdf/pypdf/pull/3964
- https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b
- https://github.com/py-pdf/pypdf/releases/tag/6.16.0