Description
Marshmallow is a lightweight library for converting complex objects to and from simple Python datatypes. In versions from 3.0.0rc1 to before 3.26.2 and from 4.0.0 to before 4.1.2, Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time. This issue has been patched in version 3.26.2 and 4.1.2.
Scores
CVSS v3
5.3
EPSS
0.0013
EPSS Percentile
32.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-405
Status
published
Products (3)
marshmallow-code/marshmallow
>= 3.0.0rc1, < 3.26.2
marshmallow-code/marshmallow
>= 4.0.0, < 4.1.2
pypi/marshmallow
3.0.0rc1 - 3.26.2PyPI
Published
Dec 22, 2025
Tracked Since
Feb 18, 2026