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Fencer Vulns
medium 5.9

CVE-2026-84373 json

Vitest: Path Traversal / Arbitrary File Read via @vitest/mocker Redirect Mock

published 2026-09-01 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-69705 , GHSA-82fw-gwwq-j7x9

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

Vitest is a testing framework powered by Vite. From 2.1.0 until 4.1.11 and 5.0.0-rc.2, the public mockerPlugin and standalone interceptorPlugin exports in packages/mocker/src/node/interceptorPlugin.ts register the vitest:interceptor:register handler on Vite's unauthenticated HMR WebSocket without validating redirect targets against the file-serving allowlist. The implementation processes event.redirect without enforcing server.fs.allow and server.fs.deny through isFileLoadingAllowed. A remote client that can reach an exposed development server can submit an opaque URL scheme preserving .. segments, causing join(server.config.root, redirectUrl.pathname) to resolve outside the project root. The plugin's load hook then returns readFile(mock.redirect, 'utf-8') as module source, disclosing local files readable by the dev-server process. Vitest browser mode uses a token-authenticated RPC and is not remotely unauthenticated by default, although the same boundary check was missing on that path. This issue is fixed in versions 4.1.11 and 5.0.0-rc.2.

Patch / fix

  • npm @vitest/mocker 4.1.11, 5.0.0-rc.2
  • npm vitest 4.1.11, 5.0.0-rc.2
  • vitest.dev vitest 4.1.11, 5.0.0-rc.2
  • vitest.dev vitest/mocker 4.1.11, 5.0.0-rc.2

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-2026-84373 updated cvss 5.9

vitest: Vitest: Arbitrary File Read via Path Traversal in HMR WebSocket

  • Red Hat AMQ Broker 7 amq-broker-bin.zip 7.14.1.CR2, amq-broker-maven-repository.zip 7.14.1.CR3
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Ansible Automation Platform 2 automation-platform-ui 2.6.13-1.el9ap, automation-gateway 2.5.20260824-1.el8ap, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat Build of Keycloak rhbk-quarkus-dist.zip 26.6.6.CR1, keycloak-operator.redhat-00001.zip 26.6.6 Red Hat Build of Podman Desktop rh-podman-desktop.git 1.1.0 Red Hat Enterprise Linux 10 rh-podman-desktop 1.1.2-1.el10_2 Red Hat JBoss Enterprise Application Platform 8 jboss-eap-runtime-maven-repository.zip 8.1.2, jboss-eap.1-runtime-maven-repository.zip 8.1.0 Red Hat JBoss Enterprise Application Platform Expansion Pack jboss-eap-runtime-maven-repository.zip 8.1.2, jboss-eap.1-runtime-maven-repository.zip 8.1.0
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Trusted Artifact Signer rhtas/rhtas-console-ui-rhel9
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Hardened Images jaeger 2.20.0-0.8.hum1, grafana13.2 13.2.0-0.1.2.hum1, prometheus3.13 3.13.2-0.2.hum1, opentelemetry-collector 0.159.0-0.1.hum1, opentelemetry-collector-k8s 0.159.0-0.1.hum1, opentelemetry-collector-contrib 0.159.0-0.1.1.hum1
    not affected: component not present

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
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 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 @vitest/mocker
>=2.1.0, <4.1.11
>=5.0.0-beta.1, <5.0.0-rc.2
4.1.11
5.0.0-rc.2
npm vitest
>=2.1.0, <4.1.11
>=5.0.0-beta.1, <5.0.0-rc.2
4.1.11
5.0.0-rc.2

Affected products

  • vitest-dev vitest
  • @vitest mocker

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.