Cross-Site Scripting (XSS) in @vitest/browser (CVE-2026-47428)
Summary
Cross-site scripting in @vitest/browser (CVE-2026-47428). Successful exploitation can lead to full system takeover. Exploitable via otelCarrier. Mitigation: upgrade to 5.0.0-beta.3 or later.
Original description
The description as published by the source.
Vitest is a testing framework powered by Vite. From 4.0.17 until 4.1.6 and 5.0.0-beta.3, Vitest Browser Mode served /vitest_test/ with the otelCarrier query parameter inserted directly into an inline module script, allowing a crafted browser-runner URL to execute arbitrary JavaScript in the Vitest server origin and recover VITEST_API_TOKEN for authenticated API calls. This issue is fixed in versions 4.1.6 and 5.0.0-beta.3.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-47428 has been found in @vitest/browser.
Attackers can target a specific entry point like otelCarrier over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.6/10.
What to do: upgrade @vitest/browser to 5.0.0-beta.3 or later.
If unsure, ask your IT team or search "@vitest/browser CVE-2026-47428" on the vendor's site.
CVE-2026-47428 (@vitest/browser) — CWE-79 / CVSS v3 9.6
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: otelCarrier / VITEST_API_TOKEN / vite.config.ts / window.VITEST_API_TOKEN
Patched: 5.0.0-beta.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in @vitest/browser. Attackers reach the vulnerable code path via otelCarrier without authentication.
Check the vendor advisory for the affected versions of @vitest/browser. Attack surface: otelCarrier / VITEST_API_TOKEN / vite.config.ts / window.VITEST_API_TOKEN.
Severity: Critical (CVSS 9.6/10). Successful exploitation can lead to full system takeover.
Update to 5.0.0-beta.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@vitest/browser' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r '@vitest/browser' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@vitest/browserを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @vitest/browser to 5.0.0-beta.3ステージング環境で 5.0.0-beta.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com