CVE-2025-66019

MEDIUM EPSS 23.0%
Published Nov 26, 20257mo ago · Modified Jun 17, 20262w ago
6.6 CVSS 4.0
Medium
Find Similar
Published Nov 26, 2025 7mo ago
Last Modified Jun 17, 2026 2w ago

Description

pypdf is a free and open-source pure-python PDF library. Prior to version 6.4.0, an attacker who uses this vulnerability can craft a PDF which leads to a memory usage of up to 1 GB per stream. This requires parsing the content stream of a page using the LZWDecode filter. This issue has been patched in version 6.4.0.

CVSS Details

Base Score
6.6
Exploitability
—
Impact
—
Vector string
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/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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
23.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-400 Uncontrolled Resource Consumption Resource Mgmt
CWE-409

References 4

  • aydinnyunus.github.io https://aydinnyunus.github.io/2025/12/20/cve-2025-66019-pypdf-lzw-dos/
  • github.com https://github.com/py-pdf/pypdf/commit/96186725e5e6f237129a58a97cd19204a9ce40b2
  • github.com https://github.com/py-pdf/pypdf/releases/tag/6.4.0
  • github.com https://github.com/py-pdf/pypdf/security/advisories/GHSA-m449-cwjh-6pw7

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.