CVE-2025-55197 MEDIUM

CVE-2025-55197: pypdf's Manipulated FlateDecode streams can exhaust RAM

Vendor Py-Pdf
Product pypdf
Weakness CWE-400
Published August 13, 2025
Last update August 14, 2025

CVSS base score

6.6/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

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/E:U

What the vulnerability does

01Description

pypdf is a free and open-source pure-python PDF library. Prior to version 6.0.0, an attacker can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access. This issue has been fixed in 6.0.0. If an update is not possible, a workaround involves including the fixed code from pypdf.filters.decompress into the existing filters file.

Key dates

02Disclosure timeline

August 13, 2025 CVE published
August 14, 2025 Record updated