Inefficient Algorithmic Complexity in PyPDF - CVE-2026-28804
Published: April 10, 2026
Vulnerability identifier: #VU125809
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-28804
CWE-ID: CWE-407
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 inefficient algorithmic complexity in the ASCIIHexDecode stream decoder when parsing a crafted PDF stream that uses the /ASCIIHexDecode filter. A remote attacker can supply a specially crafted PDF to cause a denial of service.
Exploitation requires the application to access a stream that uses the /ASCIIHexDecode filter.
How to mitigate CVE-2026-28804
Install security update from vendor's website.