CVE-2026-84311
3.3 · LOWpypdf is a free and open-source pure-python PDF library.
Overview
CVE-2026-84311 is a low-severity vulnerability affecting py-pdf pypdf. It was published on September 1, 2026 and has a CVSS 3.1 base score of 3.3 (LOW).
This vulnerability has a CVSS 3.1 base score of 3.3, rated LOW. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from py-pdf. Update pypdf to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| py-pdf | pypdf | >= 0, < 6.16.1 | Affected |
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Frequently asked questions
What is CVE-2026-84311?
CVE-2026-84311 is a low-severity vulnerability affecting py-pdf pypdf. It was published on September 1, 2026 and has a CVSS 3.1 base score of 3.3 (LOW).
How severe is CVE-2026-84311?
This vulnerability has a CVSS 3.1 base score of 3.3, rated LOW. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-84311?
Check the references section for vendor advisories and patches from py-pdf. Update pypdf to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-84311?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-84311 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.
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