# CVE-2026-84311

## Summary

- **CVE ID:** CVE-2026-84311
- **Severity:** MEDIUM
- **CVSS Score:** 4.8 (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N)
- **CWE:** CWE-834
- **Published:** Sep 1, 2026
- **Last Modified:** Sep 2, 2026

## Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.

## Affected Products

- py-pdf — pypdf (< 6.16.1)

## References

- [CNA](https://github.com/py-pdf/pypdf/security/advisories/GHSA-763m-79hh-57f2)
- [CNA](https://github.com/py-pdf/pypdf/pull/3966)
- [CNA](https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942)
- [CNA](https://github.com/py-pdf/pypdf/releases/tag/6.16.1)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.14%
- **EPSS Percentile:** 3.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._