Resource exhaustion in PyPDF - CVE-2025-55197
Published: April 10, 2026
Vulnerability identifier: #VU125806
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-55197
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Pypdf Project
Affected software:
PyPDF
PyPDF
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in FlateDecode stream processing when parsing a crafted PDF file. A remote attacker can supply a PDF with a malicious cross-reference stream using a series of FlateDecode filters to cause a denial of service.
Simply reading the file is sufficient for exploitation through a malicious cross-reference stream, while other content streams are affected on explicit access.
How to mitigate CVE-2025-55197
Install security update from vendor's website.