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CVE-2025-66019

pypdf manipulated LZWDecode streams can exhaust RAM

Published: Nov 25, 2025Updated: Jan 20, 2026 Sources: CVE List NVD GHSA BDUCWE-400
7.5HIGH
NVD MITRE
EPSS Score
0.4%
Top 72.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LC:NI:NA:H
Exploitability
AV:NAccess Vector
Network
AC:LAccess Complexity
Low
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
H
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Weaknesses

CWE-400CWE-409

Affected Products

Red Hat Inc.
commercial·USaka red hat
Red Hat OpenShift LightspeedOn-prem
Operating Systems / linux-distro
Red Hat Enterprise Linux AIOn-prem
Operating Systems / linux-distro
Ansible Automation PlatformOn-prem
Operating Systems / linux-distro
Lightspeed CoreOn-prem
Operating Systems / linux-distro
Red Hat OpenShift AIOn-prem
Operating Systems / linux-distro
ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro
Сообщество свободного программного обеспечения
oss-projectaka fsf
PyPDFLibraryLibrary
OSS Libraries / generic-library
PyPI
package-ecosystem
pypdf
OSS Libraries
py-pdf
package-ecosystemaka pypdf, pypdf2
pypdfOn-prem
OSS Libraries / pypi

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/py-pdf/pypdf/pull/3502
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jfx9-29x2-rv3j
github.com
https://github.com/py-pdf/pypdf/commit/e51d07807ffcdaf18077b9486dadb3dc05b368da
github.com
and 11 more references View all →

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