CVE-2025-68480 is a medium-severity (CVSS 5.3) CWE-405 vulnerability in marshmallow. A fix is available for marshmallow — see the affected versions and patch details below.
Marshmallow has DoS in Schema.load(many)
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-68480.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-68480 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
marshmallow🐍marshmallowReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | marshmallow | ≥ 3.0.0rc1&&< 3.26.2 | 3.26.2pip install --upgrade 'marshmallow==3.26.2' |
| 🐍PyPI | marshmallow | ≥ 4.0.0&&< 4.1.2 | 4.1.2pip install --upgrade 'marshmallow==4.1.2' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for marshmallow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update marshmallow to 3.26.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-68480 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-68480 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-68480. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-68480 in your dependencies?
O3 Security finds CVE-2025-68480 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.