PT-2026-44393 · Py Pdf · Pypdf

Published 2026-05-28 · Updated 2026-05-28 · CVE-2026-48156

NVD

CVSS v4.0

5.1

Medium

Base vector

AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.

Fix

Weakness Enumeration

CWE-834

Related Identifiers

CVE-2026-48156

Affected Products

Pypdf

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-48156 · Security Note
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6 · Note
• https://github.com/py-pdf/pypdf/pull/3791 · Note
• https://github.com/py-pdf/pypdf/releases/tag/6.12.0 · Note