CVE-2026-113793

Medium

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, removing an object from a crafted cyclic PDF tree, such as an outline item, can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1.

SeverityMedium

CVSS6.0

Exploit probability—

ProductPypdf

PublishedOct 21, 2026

First seenOct 21, 2026

Weakness typeCWE-835CWE-835

How to fix

Update

pypdf6.20.1 or later
py-pdf pypdf6.20.1 or later

Patches

github.com/py-pdf/pypdf/commit/c9c35b4471c2eb5fe078094f6c816e69d4ed25a0
github.com/py-pdf/pypdf/pull/4188
github.com/py-pdf/pypdf/security/advisories/GHSA-9mx8-4j7g-633p

Vendor advisories

github.com/py-pdf/pypdf/releases/tag/6.20.1

Affected products

Product	Affected versions	Fixed in
pypdfPyPI	v < 6.20.1	6.20.1
py-pdf pypdf	v < 6.20.1	6.20.1

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.