Description
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. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.
Scores
CVSS v3
5.5
EPSS
0.0001
EPSS Percentile
0.3%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-770
Status
published
Products (2)
pypdf_project/pypdf
< 6.7.1
pypi/pypdf
0 - 6.7.1PyPI
Published
Feb 20, 2026
Tracked Since
Feb 21, 2026