Resource exhaustion in Py-pdf Pypdf
CVE-2026-33123
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with…
Vulnerability class: DoS (Denial of Service)
EPSS: 0.003 (27.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
Affected products
- Py-pdf Pypdf — versions < 6.9.1
- Pypdf_project Pypdf
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-33123?
- CVE-2026-33123 is a medium-severity vulnerability in Py-pdf Pypdf, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-03-20.
- How severe is CVE-2026-33123?
- Medium severity. CVSS v3 base score is 6.5 out of 10.