GHSA-wgvp-vg3v-2xq3

pypdf has possible long runtimes/large memory usage for large /ToUnicode streams

Source: GitHub Advisory Database (reviewed) Moderate CVE-2026-27025

Packages

Ecosystem	Package	Affected	Fixed in
PyPI	pypdf	< 6.7.1	6.7.1

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 large memory consumption. This requires parsing the `/ToUnicode` entry of a font with unusually large values, for example during text extraction. ### Patches This has been fixed in [pypdf==6.7.1](https://github.com/py-pdf/pypdf/releases/tag/6.7.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3646](https://github.com/py-pdf/pypdf/pull/3646).

References

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

https://github.com/py-pdf/pypdf/security/advisories/GHSA-wgvp-vg3v-2xq3 web
https://nvd.nist.gov/vuln/detail/CVE-2026-27025 advisory
https://github.com/py-pdf/pypdf/pull/3646 web
https://github.com/py-pdf/pypdf/commit/77d7b8d7cfbe8dd179858dfa42666f73fc6e57a2 web
https://github.com/py-pdf/pypdf package
https://github.com/py-pdf/pypdf/releases/tag/6.7.1 web