CVE-2026-27025CWE-834

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

Medium · published February 20, 2026

CVSS v4.0
6.9
EPSS
0%
Percentile
10.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.9 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00206 · 10.1th percentile
Weakness
CWE-834 · Excessive Iteration
Published
2026-02-20T21:11Z
EPSS history
Timeline
  • 20 FEB 21:11Z
    pypdf has possible long runtimes/large memory usage for large /ToUnicode streams
    cvelistv5