CVE-2026-41312CWE-789

pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM

Medium · published April 22, 2026

CVSS v4.0
4.8
EPSS
0%
Percentile
33.7
In the wild
Unconfirmed
What it is

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to the RAM being exhausted. This requires accessing a stream compressed using `/FlateDecode` with a `/Predictor` unequal 1 and large predictor parameters. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.

The record
Technical detail
CVSS v4.0
4.8 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00406 · 33.7th percentile
Weakness
CWE-789 · Memory Allocation with Excessive Size Value
Published
2026-04-22T21:02Z
EPSS history
Timeline
  • 22 APR 21:02Z
    pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM
    cvelistv5