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Fencer Vulns
medium 5.3

CVE-2025-30359 json

webpack-dev-server users' source code may be stolen when they access a malicious web site

published 2025-06-03 17 mo ago modified 2026-09-10 1 mo ago also EUVD-2025-16767 , GHSA-4v9v-hfq4-rm2v

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

webpack-dev-server allows users to use webpack with a development server that provides live reloading. Prior to version 5.2.1, webpack-dev-server users' source code may be stolen when they access a malicious web site. Because the request for classic script by a script tag is not subject to same origin policy, an attacker can inject a malicious script in their site and run the script. Note that the attacker has to know the port and the output entrypoint script path. Combined with prototype pollution, the attacker can get a reference to the webpack runtime variables. By using `Function::toString` against the values in `__webpack_modules__`, the attacker can get the source code. Version 5.2.1 contains a patch for the issue.

Patch / fix

  • npm webpack-dev-server 5.2.1
  • webpack.js webpack-dev-server 5.2.1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-30359 updated cvss 5.3

webpack-dev-server: webpack-dev-server information exposure

  • Red Hat Cryostat 4 io.cryostat-cryostat Red Hat Migration Toolkit for Virtualization mtv-candidate/mtv-console-plugin-rhel9 Red Hat Network Observability Operator network-observability/network-observability-console-plugin-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed-tech-preview/lightspeed-console-plugin-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-hub-ui-rhel8, openshift-pipelines/pipelines-hub-ui-rhel9, openshift-pipelines/pipelines-hub-api-rhel8, openshift-pipelines/pipelines-hub-api-rhel9, openshift-pipelines/pipelines-console-plugin-rhel8, openshift-pipelines/pipelines-console-plugin-rhel9, +2 more Red Hat OpenShift Serverless openshift-serverless-1/kn-backstage-plugins-eventmesh-rhel8
    +19 more products
    Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel9, openshift-service-mesh/kiali-ossmc-rhel9, openshift-service-mesh/kiali-rhel9-operator, openshift-service-mesh/kiali-operator-bundle Red Hat Ansible Automation Platform 2 automation-gateway, automation-controller, automation-eda-controller, ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8 Red Hat build of Apache Camel - HawtIO 4 io.hawt-project Red Hat build of Apicurio Registry 2 io.apicurio-apicurio-registry Red Hat build of OptaPlanner 8 org.optaweb.vehiclerouting-optaweb-vehicle-routing Red Hat Certification for Red Hat Enterprise Linux 7 redhat-certification Red Hat Data Grid 8 org.infinispan-infinispan-console Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/rhdh-rhel9-operator Red Hat Discovery 1 discovery/discovery-ui-rhel9 Red Hat Enterprise Linux 8 pcs, grafana, pcs-snmp, grafana-loki, grafana-mssql, grafana-mysql, +11 more Red Hat Enterprise Linux 9 pcs, grafana, pcs-snmp, grafana-selinux, js-d3-flame-graph Red Hat Enterprise Linux 10 pcs, grafana, js-d3-flame-graph Red Hat Fuse 7 io.apicurio-apicurito, io.syndesis-syndesis-parent Red Hat Integration Camel K 1 io.apicurio-apicurio-registry Red Hat OpenShift AI (RHOAI) rhoai/odh-rhel8-operator, rhods/odh-rhel8-operator, rhoai/odh-dashboard-rhel8, rhods/odh-dashboard-rhel8, rhoai/odh-data-science-pipelines-argo-argoexec-rhel8, rhoai/odh-data-science-pipelines-argo-workflowcontroller-rhel8 Red Hat OpenShift distributed tracing 3 rhosdt/tempo-rhel8, rhosdt/jaeger-agent-rhel8, rhosdt/jaeger-query-rhel8, rhosdt/jaeger-ingester-rhel8, rhosdt/jaeger-rhel8-operator, rhosdt/tempo-operator-bundle, +7 more Red Hat Process Automation 7 org.uberfire-uberfire-parent Red Hat Quay 3 quay/quay-rhel8 Red Hat Trusted Profile Analyzer rhtpa/rhtpa-trustification-service-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-4v9v-hfq4-rm2v referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm webpack-dev-server
<5.2.1
5.2.1

Affected products

  • webpack webpack-dev-server

Classification

Weakness
  • CWE-749 Exposed Dangerous Method or Function

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.