Inefficient Algorithmic Complexity in PyPDF - CVE-2026-102997
Published: September 12, 2026 / Updated: October 1, 2026
Vulnerability identifier: #VU149045
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-2026-102997
CWE-ID: CWE-407
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 inefficient algorithmic complexity in byte-by-byte FlateDecode stream decompression when processing partially malformed FlateDecode streams. A remote attacker can craft a PDF to cause a denial of service.
Affected software
PyPDF
How to mitigate CVE-2026-102997
Install security update from vendor's website.
PyPDF - update to 6.18.1