Medium severity · published Oct 21, 2026
CVE-2026-113793
pypdf: Possible infinite loop when removing tree items
New
6.0
CVSS
0.5%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.20.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-113793
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113793
github.com
https://github.com/py-pdf/pypdf/commit/c9c35b4471c2eb5fe078094f6c816e69d4ed25a0
github.com
https://github.com/py-pdf/pypdf/pull/4188
github.com
https://github.com/py-pdf/pypdf/releases/tag/6.20.1
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mx8-4j7g-633p
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