Is CVE-2026-113793 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-113793 being exploited in the wild.

How severe is CVE-2026-113793?

Medium severity, with a CVSS score of 4, published 21 October 2026.

Which products and versions are affected?

Py-Pdf Pypdf before 6.20.1; pypdf (PyPI) < 6.20.1, ECOSYSTEM:introduced=0,fixed=6.20.1.

Is there a fix for CVE-2026-113793?

Yes. pypdf (PyPI): upgrade to 6.20.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-113793 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-113793?

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.

CVE-2026-113793: pypdf infinite loop in cyclic PDF tree removal

Q: Is there a fix for CVE-2026-113793?

Yes. pypdf (PyPI): upgrade to 6.20.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-113793 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-113793?

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.

CVE-2026-113793 · Severity: medium · CVSS 4 · Published 2026-10-21

pypdf is a Python library for reading and writing PDF files. When processing a specially crafted PDF with cyclic references in its outline tree, removing an object can cause the application to enter an infinite loop, resulting in a process hang or denial of service.

Technologies: Py-Pdf Pypdf, pypdf (PyPI). Vendors: Py-Pdf, PyPI.

Quick answers

Is CVE-2026-113793 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-113793 being exploited in the wild.
How severe is CVE-2026-113793?: Medium severity, with a CVSS score of 4, published 21 October 2026.
Which products and versions are affected?: Py-Pdf Pypdf before 6.20.1; pypdf (PyPI) < 6.20.1, ECOSYSTEM:introduced=0,fixed=6.20.1.
Is there a fix for CVE-2026-113793?: Yes. pypdf (PyPI): upgrade to 6.20.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-113793 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-113793?: 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 6.20.1 or later
```
pip install "pypdf>=6.20.1"
```

Technical details

The vulnerability exists in the TreeObject.remove_child method and PdfWriter.find_outline_item method, which do not properly handle cyclic references in PDF tree structures. An attacker can craft a PDF with circular pointers in the outline tree; when the vulnerable code attempts to remove or traverse such an object, it enters an infinite loop. A fix is available in version 6.20.1.

Affected products

py-pdf pypdf before 6.20.1

Identifiers

CVE-2026-113793
GHSA-9mx8-4j7g-633p

Timeline

2026-10-21: disclosed
2026-10-12: patched

References

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