Vulnerability Description
pypdf is a free and open-source pure-python PDF library. Prior to version 6.4.0, an attacker who uses this vulnerability can craft a PDF which leads to a memory usage of up to 1 GB per stream. This requires parsing the content stream of a page using the LZWDecode filter. This issue has been patched in version 6.4.0.
Related Weaknesses (CWE)
References
- https://github.com/py-pdf/pypdf/commit/96186725e5e6f237129a58a97cd19204a9ce40b2
- https://github.com/py-pdf/pypdf/releases/tag/6.4.0
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-m449-cwjh-6pw7
- https://aydinnyunus.github.io/2025/12/20/cve-2025-66019-pypdf-lzw-dos/
FAQ
What is CVE-2025-66019?
CVE-2025-66019 is a documented vulnerability. pypdf is a free and open-source pure-python PDF library. Prior to version 6.4.0, an attacker who uses this vulnerability can craft a PDF which leads to a memory usage of up to 1 GB per stream. This re...
How severe is CVE-2025-66019?
CVSS scoring is not yet available for CVE-2025-66019. Check NVD for updates.
Is there a patch for CVE-2025-66019?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.