SnakeYaml Constructor Deserialization Remote Code Execution

Exploitation

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

CVSS

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

EPSS

• CVE-2022-1471: 99.50% estimated exploitation activity in the next 30 days; percentile 99.95 (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.

Summary SnakeYaml's Constructor class, which inherits from SafeConstructor, allows any type be deserialized given the following line: new Yaml(new Constructor(TestDataClass.class)).load(yamlContent); Types do not have to match the types of properties in the target class. A ConstructorException is thrown, but only after a malicious payload is deserialized. Severity High, lack of type checks during deserialization allows remote code execution. Proof of Concept Execute bash run.sh. The PoC uses Constructor to deserialize a payload for RCE. RCE is demonstrated by using a payload which performs a http request to http://127.0.0.1:8000. Example output of successful run of proof of concept: Further Analysis Potential mitigations include, leveraging SnakeYaml's SafeConstructor while parsing untrusted content. See https://bitbucket.org/snakeyaml/snakeyaml/issues/561/cve-2022-1471-vulnerability-in#comment-64581479 for discussion on the subject. Timeline Date reported: 4/11/2022 Date fixed:…

Published by the source

12 Dec 2022, 21:19 UTC

Last modified by the source

18 Jun 2025, 17:45 UTC

Source last checked

26 Oct 2026, 16:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mjmj-j48q-9wg2

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# Patch Next advisory brief: CVE-2022-1471

Advisory: SnakeYaml Constructor Deserialization Remote Code Execution
IDs: CVE-2022-1471, GHSA-mjmj-j48q-9wg2
Record: https://patchnext.com/advisories/cve-2022-1471 (revision 1, source checked 26 Oct 2026, 16:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.yaml:snakeyaml 2.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.yaml:snakeyaml: affected <= 1.33; fixed in 2.0

## Suggested inspection (read-only)
- Maven org.yaml:snakeyaml: check the installed version with your package manager.

## 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 org.yaml:snakeyaml.
- 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://github.com/advisories/GHSA-mjmj-j48q-9wg2 (GitHub-reviewed advisory GHSA-mjmj-j48q-9wg2 lists affected ranges: Maven org.yaml:snakeyaml >=0 <=1.33)

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