CVE-2026-27888CWE-400

pypdf: Manipulated FlateDecode XFA streams can exhaust RAM

Medium · published February 26, 2026

CVSS v4.0
6.6
EPSS
1%
Percentile
53.4
In the wild
Unconfirmed
What it is

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.

The record
Technical detail
CVSS v4.0
6.6 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
EPSS
0.00720 · 53.4th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2026-02-26T00:42Z
EPSS history
Timeline
  • 26 FEB 00:42Z
    pypdf: Manipulated FlateDecode XFA streams can exhaust RAM
    cvelistv5