Description

Vitest is a testing framework powered by Vite. Prior to versions 3.2.7, 4.1.10, and 5.0.0-beta.6, Browser Mode provider commands including upload, takeScreenshot, screenshotMatcher, stopChunkTrace, deleteTracing, and annotateTraces accept browser-supplied file paths without enforcing the allowWrite permission gate or confining paths to the project root. A client that can reach the Browser Mode API can read arbitrary local files, create or overwrite image and trace files, or delete files accessible to the Vitest process even when allowWrite is false. This issue is fixed in versions 3.2.7, 4.1.10, and 5.0.0-beta.6.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.4",
  "pubDate": "2026-08-13T19:17:38.920Z",
  "pubdate": "2026-08-13T19:17:38.920Z",
  "executiveSummary": "A path traversal and access control bypass vulnerability exists in Vitest Browser Mode provider commands prior to versions 3.2.7, 4.1.10, and 5.0.0-beta.6. The flaw permits clients capable of reaching the Browser Mode API to manipulate arbitrary local files, bypassing the intended allowWrite permission gate and project root confinement restrictions. The vulnerability impacts systems running vulnerable versions of Vitest by enabling unauthorized reading, creation, overwriting, and deletion of files accessible to the execution context of the Vitest process. Attackers possessing network access to the Browser Mode API can exploit this flaw without authentication, presenting significant risk to local data confidentiality, integrity, and availability. Mitigation requires upgrading the affected Vitest installations to the patched releases where proper path validation and permission enforcement have been implemented.",
  "technicalDetails": "The root cause of the vulnerability lies in insufficient input validation and missing authorization checks within the Browser Mode provider commands of Vitest. Specifically, functions handling file operations—including upload, takeScreenshot, screenshotMatcher, stopChunkTrace, deleteTracing, and annotateTraces—accept browser-supplied file paths directly without confirming whether the operations comply with the allowWrite permission gate or remain confined within the designated project root directory.\nExploitation of this vulnerability occurs when an adversary with network reachability to the Vitest Browser Mode API submits maliciously crafted requests containing absolute paths or traversal sequences to the vulnerable provider commands. Because the Vitest process lacks adequate boundary enforcement on these incoming parameters, the application processes the paths directly against the underlying filesystem using the privileges of the running Vitest process.\nThe attack flow proceeds as follows: First, the attacker identifies or establishes network access to the exposed Vitest Browser Mode API endpoint. Second, the attacker crafts API payloads targeting functions such as upload or takeScreenshot, embedding arbitrary local file paths outside the project workspace. Third, the Vitest process executes the requested file-handling operations—such as reading sensitive system files, generating or overwriting image and trace files at arbitrary locations, or deleting targeted filesystem objects—despite the allowWrite configuration being set to false or restricted.\nThe vulnerable components are the Browser Mode provider command handlers responsible for file I/O operations within Vitest. Affected versions comprise all releases prior to 3.2.7, 4.1.10, and 5.0.0-beta.6. Exploitation requires neither authentication nor elevated privileges beyond network reachability to the API. Post-exploitation impact includes unauthorized disclosure of local file contents, compromise of filesystem integrity through file creation and overwriting, and localized denial of service via file deletion."
}