Vulnerability in Py-Pdf Pypdf

CVE-2026-27025

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, 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. This vulnerability is fixed in 6.7.1.

EPSS: 0.002 (6.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-27025?
CVE-2026-27025 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Excessive Iteration. CVSS score: 5.5/10. Published 2026-02-20.
How severe is CVE-2026-27025?
Medium severity. CVSS v3 base score is 5.5 out of 10.