GHSA-qpxp-75px-xjcp

pypdf has inefficient decoding of array-based streams

Source: GitHub Advisory Database (reviewed) Moderate CVE-2026-33123

Packages

Ecosystem	Package	Affected	Fixed in
PyPI	pypdf	< 6.9.1	6.9.1

Details

As written in the advisory (Markdown source, shown as plain text).

### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and/or large memory usage. This requires accessing an array-based stream with lots of entries. ### Patches This has been fixed in [pypdf==6.9.1](https://github.com/py-pdf/pypdf/releases/tag/6.9.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3686](https://github.com/py-pdf/pypdf/pull/3686).

References

External links from the advisory. They lead to third-party sites.

https://github.com/py-pdf/pypdf/security/advisories/GHSA-qpxp-75px-xjcp web
https://nvd.nist.gov/vuln/detail/CVE-2026-33123 advisory
https://github.com/py-pdf/pypdf/pull/3686 web
https://github.com/py-pdf/pypdf package
https://github.com/py-pdf/pypdf/releases/tag/6.9.1 web