Marshmallow has DoS in Schema.load(many)
Impact
Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time.
Patches
4.1.2, 3.26.2
Workarounds
# Fail fast
def load_many(schema, data, **kwargs):
if not isinstance(data, list):
raise ValidationError(['Invalid input type.'])
return [schema.load(item, **kwargs) for item in data]Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | marshmallow | >= 3.0.0rc1, < 3.26.2, >= 4.0.0, < 4.1.2 | 3.26.2, 4.1.2 |
References
- https://github.com/marshmallow-code/marshmallow/security/advisories/GHSA-428g-f7cq-pgp5
- https://nvd.nist.gov/vuln/detail/CVE-2025-68480
- https://github.com/marshmallow-code/marshmallow/commit/d24a0c9df061c4daa92f71cf85aca25b83eee508
- https://github.com/marshmallow-code/marshmallow
- https://pypi.org/project/marshmallow
- https://github.com/advisories/GHSA-428g-f7cq-pgp5
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- Weakness (CWE)
CWE-405- Platform
- Python (PyPI)
- Package
marshmallow- Disclosed
- 22.12.2025
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-1605 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-428g-f7cq-pgp5 - CC BY 4.0
Vulnerability history: marshmallow
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 09.2018 12.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
Disclosures per year
- 2018: 1
- 2019: 0
- 2020: 0
- 2021: 0
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 1
- 2026: 0
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Marshmallow has DoS in Schema.load(many) this entry
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