Path Traversal in @vitest/browser (CVE-2026-73653)
Summary
Path traversal in @vitest/browser (CVE-2026-73653). Confidential information can be exposed externally. Exploitable via allowWrite. Mitigation: upgrade to 5.0.0-beta.6 or later.
Original description
The description as published by the source.
Summary
Browser Mode exposes a set of built-in "commands" that run on the Node.js side of the test runner and can touch the local filesystem (taking screenshots, managing Playwright traces, uploading files for ``, comparing screenshots).
Several of these commands accept a file path from the browser and act on it without checking the allowWrite permission gate and without confining the path to the project directory. A client that can reach the Browser Mode API can therefore read, create, overwrite, or delete files anywhere the Vitest process can access, even when allowWrite is false.
This matters most when the Browser Mode API is exposed to the network (for example test.api.host is set, or the dev server is reachable from another machine or origin). In that configuration allowWrite defaults to false precisely to block file access, and these commands bypass that protection. On a default localhost-only setup with trusted test code, there is no untrusted party in a position to exploit it. The gap still matters wherever you rely on allowWrite: false to contain untrusted test code, because these commands ignore that flag.
Affected commands and impact
| Command | Operation | Impact |
|---|---|---|
upload (Playwright + WebdriverIO) |
Read | Arbitrary local file read; contents are loaded into the page and readable by test code. Highest-impact case. |
takeScreenshot (Playwright + WebdriverIO) |
Write | Writes a PNG to an arbitrary path (absolute path us… |
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-2026-73653 has been found in @vitest/browser.
Attackers can target a specific entry point like allowWrite over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.4/10.
What to do: upgrade @vitest/browser to 5.0.0-beta.6 or later.
If unsure, ask your IT team or search "@vitest/browser CVE-2026-73653" on the vendor's site.
CVE-2026-73653 (@vitest/browser) — CWE-22 / CVSS v3 9.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: allowWrite / false / test.api.host / upload
Patched: 5.0.0-beta.6 — 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.
Path traversal (CWE-22) exists in @vitest/browser. Attackers reach the vulnerable code path via allowWrite without authentication.
Check the vendor advisory for the affected versions of @vitest/browser. Attack surface: allowWrite / false / test.api.host / upload.
Severity: Critical (CVSS 9.4/10). Confidential information can be exposed externally.
Update to 5.0.0-beta.6.
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
-
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.6ステージング環境で 5.0.0-beta.6 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
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web security-advisories@github.com
- web github.com