Infinite loop in PyPDF - CVE-2026-113793
Published: October 21, 2026 / Updated: October 23, 2026
Vulnerability identifier: #VU156649
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-113793
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a loop with an unreachable exit condition in pypdf's tree-item removal functionality when removing an object, such as an outline item, from a PDF tree. A remote attacker can supply a specially crafted PDF that causes this operation to loop indefinitely to cause a denial of service.
Affected software
PyPDF
How to mitigate CVE-2026-113793
Install security update from vendor's website.
PyPDF - update to 6.20.1