Pdfly: pypdf: Possible infinite loop for TreeObject.insert_child (CVE-2026-84309)
A vulnerability in the pdfly product's pypdf component allows an attacker to craft a malicious PDF that triggers an infinite loop in the TreeObject.insert_child function. This can cause denial of service by hanging the application processing the PDF. The issue affects versions from 0.4.0 up to but not including 0.5.1_25. A fix is available in pypdf version 6.16.0. If upgrading is not immediately possible, applying the changes from the referenced pull request is recommended as a workaround.
AI Analysis
Technical Summary
CVE-2026-84309 describes a denial-of-service vulnerability in pdfly's pypdf library where a specially crafted PDF can cause an infinite loop in the TreeObject.insert_child method. This requires the code path to invoke this method, typically during PDF writing operations. The vulnerability is patched in pypdf version 6.16.0. The affected versions are >=0.4.0 and <0.5.1_25. No known exploits are reported in the wild.
Potential Impact
An attacker can cause an application using the vulnerable pypdf versions to enter an infinite loop when processing a malicious PDF, leading to denial of service. There is no indication of privilege escalation, data disclosure, or code execution. The impact is limited to availability disruption.
Mitigation Recommendations
Upgrade to pypdf version 6.16.0 or later to fully remediate the vulnerability. If immediate upgrade is not feasible, apply the code changes from pull request #3964 as a temporary workaround.
Pdfly: pypdf: Possible infinite loop for TreeObject.insert_child (CVE-2026-84309)
Description
A vulnerability in the pdfly product's pypdf component allows an attacker to craft a malicious PDF that triggers an infinite loop in the TreeObject.insert_child function. This can cause denial of service by hanging the application processing the PDF. The issue affects versions from 0.4.0 up to but not including 0.5.1_25. A fix is available in pypdf version 6.16.0. If upgrading is not immediately possible, applying the changes from the referenced pull request is recommended as a workaround.
CVSS v4.0
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-84309 describes a denial-of-service vulnerability in pdfly's pypdf library where a specially crafted PDF can cause an infinite loop in the TreeObject.insert_child method. This requires the code path to invoke this method, typically during PDF writing operations. The vulnerability is patched in pypdf version 6.16.0. The affected versions are >=0.4.0 and <0.5.1_25. No known exploits are reported in the wild.
Potential Impact
An attacker can cause an application using the vulnerable pypdf versions to enter an infinite loop when processing a malicious PDF, leading to denial of service. There is no indication of privilege escalation, data disclosure, or code execution. The impact is limited to availability disruption.
Mitigation Recommendations
Upgrade to pypdf version 6.16.0 or later to fully remediate the vulnerability. If immediate upgrade is not feasible, apply the code changes from pull request #3964 as a temporary workaround.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- BREW-pdfly-CVE-2026-84309
- Osv Schema Version
- 1.7.3
- Ecosystems
- ["Homebrew"]
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac1396ca43b0b3b89d5fdd4
Added to database: 10/03/2026, 17:20:44 UTC
Last enriched: 10/03/2026, 17:25:44 UTC
Last updated: 10/04/2026, 02:46:07 UTC
Views: 2
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