py-pdf pypdf up to 6.21.3 infinite loop

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.1$0-$5k2.73-

Summaryinfo

A vulnerability, which was classified as problematic, was found in py-pdf pypdf up to 6.21.3. This affects an unknown function. The manipulation results in infinite loop. This vulnerability is identified as CVE-2026-119205. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in py-pdf pypdf up to 6.21.3. It has been classified as problematic. Affected is some unknown functionality. The manipulation with an unknown input leads to a infinite loop vulnerability. CWE is classifying the issue as CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-119205 since 10/29/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 6.21.4 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: pypdf 6.21.4

Timelineinfo

10/29/2026 Advisory disclosed
10/29/2026 +0 days CVE reserved
10/29/2026 +0 days VulDB entry created
10/29/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CNA: GitHub_M
CVE: CVE-2026-119205 (🔒)

GCVE (CVE): GCVE-0-2026-119205
GCVE (VulDB): GCVE-100-428766

Entryinfo

Created: 10/29/2026 21:59
Changes: 10/29/2026 21:59 (66)
Complete: 🔍
Cache ID: 216::103

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