{"uuid": "177dd7ef-23d3-4192-a2b7-e5a0f03a7844", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-84310", "type": "seen", "source": "https://gist.github.com/alon710/3521e58613b990dddef5bf0335b08c88", "content": "# CVE-2026-84310: CVE-2026-84310: Algorithmic Complexity Exhaustion in pypdf\n\n> **CVSS Score:** 4.8\n> **Published:** 2026-09-01\n> **Full Report:** https://cvereports.com/reports/CVE-2026-84310\n\n## Summary\nAn algorithmic complexity vulnerability in the pypdf library before version 6.16.1 allows remote or local attackers to cause an application denial of service. The flaw is triggered via maliciously crafted PDF documents that utilize either deeply nested outlines or exponential Directed Acyclic Graph (DAG) structures in Form XObjects.\n\n## TL;DR\nA resource exhaustion vulnerability in pypdf allows local and remote denial of service via unbounded recursion in outline retrieval and exponential node expansion in Form XObject parsing.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-405, CWE-834\n- **Attack Vector**: Local / User Interaction (Parsing a maliciously crafted PDF file)\n- **CVSS v4.0 Score**: 4.8\n- **Impact**: Denial of Service (CPU & Memory Exhaustion)\n- **Exploit Status**: Proof of Concept (PoC) documented\n- **KEV Status**: Not Listed\n\n## Affected Systems\n\n- Applications utilizing the pypdf Python library for PDF parsing, text extraction, or outline processing.\n- **pypdf**: < 6.16.1 (Fixed in: `6.16.1`)\n\n## Mitigation\n\n- Upgrade the pypdf library to version 6.16.1 or higher.\n- Implement process-level execution timeouts for all document parsing tasks.\n- Deploy static analysis detection rules to identify anomalously structured PDF files before processing.\n\n**Remediation Steps:**\n1. Identify all microservices and processing pipelines using the pypdf dependency.\n2. Update requirements.txt, Pipfile, or pyproject.toml to enforce pypdf>=6.16.1.\n3. Run pip install --upgrade pypdf to apply the security patch locally and in CI/CD environments.\n4. Configure OS-level resource limits or Celery worker timeouts to automatically terminate long-running parsing tasks.\n\n## References\n\n- [GitHub Advisory GHSA-23w6-3w8w-8484](https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484)\n- [Fix Commit](https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942)\n- [Pull Request #3966](https://github.com/py-pdf/pypdf/pull/3966)\n- [Release 6.16.1](https://github.com/py-pdf/pypdf/releases/tag/6.16.1)\n- [CVE-2026-84310 Record](https://www.cve.org/CVERecord?id=CVE-2026-84310)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/CVE-2026-84310) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-09-02T03:31:51.137091Z"}