Answer in brief
CVE-2026-84309 records a Medium severity (CVSS 0.0) vulnerability in pypdf: Possible infinite loop for TreeObject.insert_child. The current sources do not mark it as known exploited. The current feed maps py-pdf/pypdf (generic), pypdf (pip), pypdf (pypi). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 0.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps py-pdf/pypdf (generic), pypdf (pip), pypdf (pypi). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| py-pdf/pypdfgeneric | <6.16.0 | 6.16.0 |
| pypdfpip | <6.16.0 | 6.16.0 |
| pypdfpypi | >=0 <6.16.0 | 6.16.0 |
Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.
Quoted source text, attributed separately from HOL analysis.