CVE-2026-119205
Published:October 29, 2026
Updated:October 30, 2026
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop when cloning or duplicating a crafted cyclic DictionaryObject. Clone traversal checked generated destination references rather than the original source references, allowing some source cycles to evade the visited-object check. This issue is fixed in version 6.21.4.
Affected Packages
pypdf (CONDA):
Affected version(s) >=4.0.0 <6.21.4 || >=5.0.0 <6.21.4 || >=6.0.0 <6.21.4 || >=3.2.0 <6.21.4Fix Suggestion:
Update to version 6.21.4https://github.com/py-pdf/pypdf.git (GITHUB):
Affected version(s) >=3.0.0 <6.21.4 || >=4.0.0 <6.21.4 || >=5.0.0 <6.21.4 || >=6.0.0 <6.21.4Fix Suggestion:
Update to version 6.21.4pypdf (PYTHON):
Affected version(s) >=4.0.0 <6.21.4 || >=5.0.0 <6.21.4 || >=3.1.0 <6.21.4 || >=6.0.0 <6.21.4Fix Suggestion:
Update to version 6.21.4Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Loop with Unreachable Exit Condition