Excessive Iteration in PyPDF - CVE-2026-27025
Published: February 20, 2026
Vulnerability identifier: #VU123111
CSH Severity: Medium
CVSS v4.0: 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/U:Green
CVE-ID: CVE-2026-27025
CWE-ID: CWE-834
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 perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input within /ToUnicode streams. A remote attacker can use a specially crafted PDF and perform a denial of service (DoS) attack.
How to mitigate CVE-2026-27025
Install updates from vendor's website.