CVE-2026-115580: CWE-834: Excessive Iteration in py-pdf pypdf
Description
A vulnerability in the pypdf library prior to version 6.21.2 allows an attacker to craft a PDF file with a cross-reference table declaring more entries than the file actually contains. This causes the library to perform excessive iteration, leading to long processing times when opening the file. The issue is addressed in version 6.21.2.
CVSS v4.0
Score 7.1high
Affected software
py-pdf
pypdf
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The pypdf library, a pure-Python PDF processing tool, has a vulnerability identified as CWE-834 (Excessive Iteration). In versions before 6.21.2, an attacker can create a malicious PDF with a standard cross-reference table that declares an entry count larger than the actual number of entries. When pypdf processes such a file, it performs excessive iteration, resulting in prolonged runtimes and potential denial of service due to resource exhaustion. This vulnerability has a CVSS 4.0 score of 7.1, indicating high severity. The issue is fixed in pypdf version 6.21.2.
Potential Impact
An attacker can cause a denial of service by crafting a PDF that triggers excessive processing in pypdf, leading to long runtimes and potential resource exhaustion on systems that open the malicious PDF. There is no indication of code execution or data disclosure from the provided information.
Mitigation Recommendations
Upgrade pypdf to version 6.21.2 or later, where this vulnerability is fixed. No other mitigation is indicated or necessary according to the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-22T22:53:15.238Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6adbbaa6d73cc49347b780eb
Added to database: 10/23/2026, 19:51:02 UTC
Last enriched: 10/23/2026, 20:05:11 UTC
Last updated: 10/23/2026, 20:05:11 UTC
Views: 6
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