# CVE-2026-113795: pypdf memory exhaustion via crafted PDF streams

Source: https://junglewise.ai/threats/cve-2026-113795-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-113795 · Severity: medium · CVSS 4 · Published 2026-10-21

pypdf is a Python library for reading and manipulating PDF files. A malicious or crafted PDF file with excessive filters or filter chains can cause the application to consume large amounts of memory, potentially causing the application to crash or hang. An attacker could exploit this by distributing a crafted PDF that exhausts system resources when processed.

Technologies: [Py-Pdf Pypdf](https://junglewise.ai/threats/technologies/py-pdf-pypdf), [pypdf (PyPI)](https://junglewise.ai/threats/technologies/pypdf). Vendors: [Py-Pdf](https://junglewise.ai/threats/vendors/py-pdf), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-113795 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-113795 being exploited in the wild.

**How severe is CVE-2026-113795?** Medium severity, with a CVSS score of 4, published 21 October 2026.

**Which products and versions are affected?** Py-Pdf Pypdf prior to 6.20.0; pypdf (PyPI) < 6.20.0, ECOSYSTEM:introduced=0,fixed=6.20.0.

**Is there a fix for CVE-2026-113795?** Yes. pypdf (PyPI): upgrade to 6.20.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-113795 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-113795?** Check whether you run Py-Pdf Pypdf or pypdf (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- pypdf (PyPI): upgrade to 6.20.0 or later

  ```sh
  pip install "pypdf>=6.20.0"
  ```


## Technical details

A PDF stream with a large number of filters or multiple filters that process large amounts of data can trigger excessive memory allocation during decompression. The vulnerability affects PDF parsing when accessing stream objects with malformed or abusive filter configurations. The fix introduces limits on filter count and accumulated decoding work per stream to prevent resource exhaustion.

## Affected products

- py-pdf pypdf prior to 6.20.0

## Identifiers

- CVE-2026-113795
- GHSA-7mh2-4gg2-979f

## Timeline

- 2026-10-21: disclosed

## References

- [https://github.com/py-pdf/pypdf/commit/80a84d4be6022d910874ccb0d2365400f3f0e185](https://github.com/py-pdf/pypdf/commit/80a84d4be6022d910874ccb0d2365400f3f0e185)
- [https://github.com/py-pdf/pypdf/pull/4173](https://github.com/py-pdf/pypdf/pull/4173)

## Related threats

- [pypdf memory exhaustion in cross-reference stream parsing](https://junglewise.ai/threats/cve-2026-119209-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf denial of service via forged encrypted PDF page count](https://junglewise.ai/threats/cve-2026-119208-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf excessive memory consumption in strict mode PDF parsing](https://junglewise.ai/threats/cve-2026-119207-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf denial of service via crafted page labels](https://junglewise.ai/threats/cve-2026-119206-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)
- [pypdf infinite loop in DictionaryObject cloning](https://junglewise.ai/threats/cve-2026-119205-pypdf-is-a-free-and-open-source-pure-python-pdf-library-prior-to)