You are viewing this page in an unauthorized frame window.
This is a potential security issue, you are being redirected to
https://nvd.nist.gov
An official website of the United States government
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.
Description
flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "__proto__" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
By selecting these links, you will be leaving NIST webspace.
We have provided these links to other web sites because they
may have information that would be of interest to you. No
inferences should be drawn on account of other sites being
referenced, or not, from this page. There may be other web
sites that are more appropriate for your purpose. NIST does
not necessarily endorse the views expressed, or concur with
the facts presented on these sites. Further, NIST does not
endorse any commercial products that may be mentioned on
these sites. Please address comments about this page to [email protected].
[{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.8","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.8::el9"]},{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.9","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.9::el9"]},{"vendor":"Red Hat","product":"Red Hat 3scale API Management Platform 2","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_3scale_amp:2"]},{"vendor":"Red Hat","product":"Red Hat Build of Keycloak","defaultStatus":"affected","cpes":["cpe:/a:redhat:build_keycloak:"]},{"vendor":"Red Hat","product":"Red Hat Single Sign-On 7","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_single_sign_on:7"]},{"vendor":"Red Hat","product":"Cryostat 4","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:cryostat:4"]},{"vendor":"Red Hat","product":"Logging Subsystem for Red Hat OpenShift","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:logging:5"]},{"vendor":"Red Hat","product":"Multicluster Engine for Kubernetes","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:multicluster_engine"]},{"vendor":"Red Hat","product":"Red Hat Advanced Cluster Management for Kubernetes 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:acm:2"]},{"vendor":"Red Hat","product":"Red Hat AMQ Broker 7","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:amq_broker:7"]},{"vendor":"Red Hat","product":"Red Hat build of Apicurio Registry 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:service_registry:2"]},{"vendor":"Red Hat","product":"Red Hat build of OptaPlanner 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:optaplanner:::el6"]},{"vendor":"Red Hat","product":"Red Hat Build of Podman Desktop","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:podman_desktop:1"]},{"vendor":"Red Hat","product":"Red Hat Data Grid 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:jboss_data_grid:8"]},{"vendor":"Red Hat","product":"Red Hat Directory Server 11","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:directory_server:11"]},{"vendor":"Red Hat","product":"Red Hat Directory Server 12
[{"vendor":"Red Hat","product":"Cluster Observability Operator 1.5.0","defaultStatus":"affected","cpes":["cpe:/a:redhat:cluster_observability_operator:1.5::el9"]},{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.8","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.8::el9"]},{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.9","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.9::el9"]},{"vendor":"Red Hat","product":"Red Hat 3scale API Management Platform 2","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_3scale_amp:2"]},{"vendor":"Red Hat","product":"Red Hat Build of Keycloak","defaultStatus":"affected","cpes":["cpe:/a:redhat:build_keycloak:"]},{"vendor":"Red Hat","product":"Red Hat Single Sign-On 7","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_single_sign_on:7"]},{"vendor":"Red Hat","product":"Cryostat 4","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:cryostat:4"]},{"vendor":"Red Hat","product":"Logging Subsystem for Red Hat OpenShift","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:logging:5"]},{"vendor":"Red Hat","product":"Multicluster Engine for Kubernetes","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:multicluster_engine"]},{"vendor":"Red Hat","product":"Red Hat Advanced Cluster Management for Kubernetes 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:acm:2"]},{"vendor":"Red Hat","product":"Red Hat AMQ Broker 7","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:amq_broker:7"]},{"vendor":"Red Hat","product":"Red Hat build of Apicurio Registry 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:service_registry:2"]},{"vendor":"Red Hat","product":"Red Hat build of OptaPlanner 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:optaplanner:::el6"]},{"vendor":"Red Hat","product":"Red Hat Build of Podman Desktop","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:podman_desktop:1"]},{"vendor":"Red Hat","product":"Red Hat Data Grid 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:jboss_data_grid:8"]},{"vendor":"Red Hat","product":"
[{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.8","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.8::el9"]},{"vendor":"Red Hat","product":"Red Hat Developer Hub 1.9","defaultStatus":"affected","cpes":["cpe:/a:redhat:rhdh:1.9::el9"]},{"vendor":"Red Hat","product":"Red Hat 3scale API Management Platform 2","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_3scale_amp:2"]},{"vendor":"Red Hat","product":"Red Hat Build of Keycloak","defaultStatus":"affected","cpes":["cpe:/a:redhat:build_keycloak:"]},{"vendor":"Red Hat","product":"Red Hat Single Sign-On 7","defaultStatus":"affected","cpes":["cpe:/a:redhat:red_hat_single_sign_on:7"]},{"vendor":"Red Hat","product":"Cryostat 4","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:cryostat:4"]},{"vendor":"Red Hat","product":"Logging Subsystem for Red Hat OpenShift","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:logging:5"]},{"vendor":"Red Hat","product":"Multicluster Engine for Kubernetes","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:multicluster_engine"]},{"vendor":"Red Hat","product":"Red Hat Advanced Cluster Management for Kubernetes 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:acm:2"]},{"vendor":"Red Hat","product":"Red Hat AMQ Broker 7","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:amq_broker:7"]},{"vendor":"Red Hat","product":"Red Hat build of Apicurio Registry 2","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:service_registry:2"]},{"vendor":"Red Hat","product":"Red Hat build of OptaPlanner 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:optaplanner:::el6"]},{"vendor":"Red Hat","product":"Red Hat Build of Podman Desktop","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:podman_desktop:1"]},{"vendor":"Red Hat","product":"Red Hat Data Grid 8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:jboss_data_grid:8"]},{"vendor":"Red Hat","product":"Red Hat Directory Server 11","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:directory_server:11"]},{"vendor":"Red Hat","product":"Red Hat Directory Server 12
New CVE Received from GitHub, Inc.3/20/2026 7:16:46 PM
Action
Type
Old Value
New Value
Added
Description
flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "__proto__" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.
) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
