CVE-2025-66019: pypdf's LZWDecode streams be manipulated to exhaust RAM
(updated )
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 is a follow up to GHSA-jfx9-29x2-rv3j to align the default limit with the one for zlib.
References
- github.com/advisories/GHSA-m449-cwjh-6pw7
- github.com/py-pdf/pypdf
- github.com/py-pdf/pypdf/commit/96186725e5e6f237129a58a97cd19204a9ce40b2
- github.com/py-pdf/pypdf/releases/tag/6.4.0
- github.com/py-pdf/pypdf/security/advisories/GHSA-jfx9-29x2-rv3j
- github.com/py-pdf/pypdf/security/advisories/GHSA-m449-cwjh-6pw7
- nvd.nist.gov/vuln/detail/CVE-2025-66019
Code Behaviors & Features
Detect and mitigate CVE-2025-66019 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →