CVE-2022-31605 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in nvflare. A fix is available for nvflare — see the affected versions and patch details below.
Unsafe yaml deserialization in NVFlare
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-2022-31605 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 378,156 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
nvflareReal-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
Impact
NVFLARE contains a vulnerability in its utils module, where YAML files are loaded via yaml.load() instead of yaml.safe_load(). The deserialization of Untrusted Data, may allow an unprivileged network attacker to cause Remote Code Execution, Denial Of Service, and Impact to both Confidentiality and Integrity.
All versions before 2.1.2 are affected. CVSS Score = 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Patches
The patch will be included in nvflare==2.1.2
Workarounds
Change yaml.load() to yaml.safe_load()
Additional information
Issue Found by: Oliver Sellwood (@Nintorac)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | nvflare | all versions | 2.1.2pip install --upgrade 'nvflare==2.1.2' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nvflare, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nvflare to 2.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31605 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-2022-31605 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-31605. 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-2022-31605 in your dependencies?
O3 Security finds CVE-2022-31605 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.