CVE-2026-33123 MEDIUM

CVE-2026-33123: pypdf has inefficient decoding of array-based streams

Vendor Py-Pdf
Product pypdf
Weakness CWE-400
Published March 20, 2026
Last update March 20, 2026
View on NVD All CVEs

CVSS base score

5.1/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.

Key dates

02Disclosure timeline

March 20, 2026 CVE published
March 20, 2026 Record updated