Unsafe yaml deserialization in NVFlare

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2022-31605: 2.13% estimated exploitation activity in the next 30 days; percentile 81.97 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact NVFLARE contains a vulnerability in its utils module, where YAML files are loaded via yaml.load() instead of yaml.safeload(). 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.safeload() Additional information Issue Found by: Oliver Sellwood (@Nintorac)

Published by the source

22 Jun 2022, 21:22 UTC

Last modified by the source

8 Jul 2026, 06:30 UTC

Source last checked

26 Oct 2026, 13:12 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hrf3-622q-8366

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hrf3-622q-8366

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# Patch Next advisory brief: CVE-2022-31605

Advisory: Unsafe yaml deserialization in NVFlare
IDs: CVE-2022-31605, GHSA-hrf3-622q-8366
Record: https://patchnext.com/advisories/cve-2022-31605 (revision 2, source checked 26 Oct 2026, 13:12 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nvflare 2.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI nvflare: affected < 2.1.2; fixed in 2.1.2

## Suggested inspection (read-only)
- `python -m pip show nvflare`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nvflare.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hrf3-622q-8366 (OSV record GHSA-hrf3-622q-8366 lists affected ranges: PyPI nvflare >=0 <2.1.2 (fixed))
- Verified: https://github.com/advisories/GHSA-hrf3-622q-8366 (GitHub-reviewed advisory GHSA-hrf3-622q-8366 lists affected ranges: PyPI nvflare >=0 <2.1.2)

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