Resource exhaustion in PyPDF - CVE-2026-57204
Published: June 23, 2026
Vulnerability identifier: #VU135040
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-57204
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause excessive memory consumption.
The vulnerability exists due to uncontrolled resource consumption in content stream parsing when processing a PDF content stream without a /Length value. A remote attacker can supply a specially crafted PDF to cause excessive memory consumption.
The issue occurs because MAX_DECLARED_STREAM_LENGTH is sometimes ignored.
Affected software
PyPDF
How to mitigate CVE-2026-57204
Install security update from vendor's website.
PyPDF - update to 6.13.3