medium4.8
CVE-2026-84311
pypdf: Possible long runtimes/large memory usage when extracting XForm objects
Impact
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.16.1 | 6.16.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.16.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-763m-79hh-57f2
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-763m-79hh-57f2
- https://github.com/py-pdf/pypdf/pull/3966
- https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942
- https://github.com/py-pdf/pypdf/releases/tag/6.16.1