Vulnerability in Py-Pdf Pypdf
CVE-2026-28804
pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5.
EPSS: 0.004 (32.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Py-pdf Pypdf — versions < 6.7.5
- 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 (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-28804?
- CVE-2026-28804 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Inefficient Algorithmic Complexity. CVSS score: 5.3/10. Published 2026-03-06.
- How severe is CVE-2026-28804?
- Medium severity. CVSS v3 base score is 5.3 out of 10.