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CVE-2026-33123

pypdf has inefficient decoding of array-based streams

Published: Mar 20, 2026Updated: Mar 23, 2026 Sources: CVE List NVD BDUCWE-400
6.5MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 72.4%
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. 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 many entries. This issue has been fixed in version 6.9.1.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-400CWE-407

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
py-pdf
package-ecosystemaka pypdf, pypdf2
pypdfOn-prem
OSS Libraries / pypi
pypdf project
oss-project
pypdfLibrary
OSS Libraries / generic-library

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/releases/tag/6.9.1
github.com
https://github.com/py-pdf/pypdf/pull/3686
github.com
https://github.com/py-pdf/pypdf
github.com
and 6 more references View all →

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