CVE-2026-103000: CWE-400: Uncontrolled Resource Consumption in py-pdf pypdf
pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory and potentially making the application unavailable. This issue is fixed in version 6.19.0.
AI Analysis
Technical Summary
The vulnerability in pypdf (CVE-2026-103000) arises from the handling of page labels in PDF documents. Specifically, crafted PDFs can contain very large alphabetical page-label values that cause the _page_labels.py module to generate excessively long strings. This uncontrolled resource consumption can exhaust memory resources and cause denial of service by making the application unavailable. The flaw is addressed by an official fix in version 6.19.0 of pypdf.
Potential Impact
Exploitation of this vulnerability can lead to denial of service due to excessive memory consumption when processing maliciously crafted PDFs. This may cause the affected application using pypdf to become unavailable or crash. There is no indication of privilege escalation, data disclosure, or code execution from the provided data.
Mitigation Recommendations
Upgrade pypdf to version 6.19.0 or later, where this vulnerability has been fixed. No other mitigation is required as the official fix addresses the issue.
CVE-2026-103000: CWE-400: Uncontrolled Resource Consumption in py-pdf pypdf
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory and potentially making the application unavailable. This issue is fixed in version 6.19.0.
CVSS v4.0
Score 8.7high
Affected software
py-pdf
pypdf
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in pypdf (CVE-2026-103000) arises from the handling of page labels in PDF documents. Specifically, crafted PDFs can contain very large alphabetical page-label values that cause the _page_labels.py module to generate excessively long strings. This uncontrolled resource consumption can exhaust memory resources and cause denial of service by making the application unavailable. The flaw is addressed by an official fix in version 6.19.0 of pypdf.
Potential Impact
Exploitation of this vulnerability can lead to denial of service due to excessive memory consumption when processing maliciously crafted PDFs. This may cause the affected application using pypdf to become unavailable or crash. There is no indication of privilege escalation, data disclosure, or code execution from the provided data.
Mitigation Recommendations
Upgrade pypdf to version 6.19.0 or later, where this vulnerability has been fixed. No other mitigation is required as the official fix addresses the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-29T20:46:08.335Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abd72552a4e24523d8ec0ef
Added to database: 09/30/2026, 20:34:29 UTC
Last enriched: 09/30/2026, 20:47:55 UTC
Last updated: 10/01/2026, 03:54:08 UTC
Views: 9
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