Excessive Iteration in PyPDF - #VU143597
Published: August 16, 2026
Vulnerability identifier: #VU143597
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-834
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 excessive iteration in outline processing when retrieving document outlines from a crafted PDF with many entries or nested outlines with long re-used nesting paths. A remote attacker can supply a specially crafted PDF to cause a denial of service.
The issue is triggered when the application accesses the outlines of the document.
Affected software
PyPDF
Remediation
Install security update from vendor's website.
PyPDF - update to 6.16.1