Appium: Reflected XSS / arbitrary JS in @appium/base-driver /test/guinea-pig* routes

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-58191: 0.56% estimated exploitation activity in the next 30 days; percentile 46.94 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Appium's base-driver mounts the built-in /test/guinea-pig, /test/guinea-pig-scrollable and /test/guinea-pig-app-banner routes unconditionally on every server. The handler reflects the throwError query param, the comments POST field, and the User-Agent request header into the returned HTML via compileLodashTemplate, which interpolates <%= expr % as String(expr) with no HTML/JS escaping. This yields reflected XSS, and the throwError value is reflected inside a <script block, giving arbitrary JavaScript execution on the server's origin. No authentication, no session, no driver and no plugin are required, and the default bind address is 0.0.0.0. Details Affected - @appium/base-driver 10.6.0 (with Appium server 3.5.0); tested live. - Template engine helper: @appium/base-driver lib/utils.ts compileLodashTemplate. Location (file:line) - Routes mounted unconditionally: base-driver/lib/express/server.ts:216-219 (app.all('/test/guinea-pig', guineaPig) etc.). - Tainting:…

Published by the source

1 Sep 2026, 18:54 UTC

Last modified by the source

1 Sep 2026, 18:54 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3wgp-x9p5-c7cc

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# Patch Next advisory brief: CVE-2026-58191

Advisory: Appium: Reflected XSS / arbitrary JS in @appium/base-driver /test/guinea-pig* routes
IDs: CVE-2026-58191, GHSA-3wgp-x9p5-c7cc
Record: https://patchnext.com/advisories/cve-2026-58191 (revision 1, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @appium/base-driver 10.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @appium/base-driver: affected <= 10.6.0; fixed in 10.7.0

## Suggested inspection (read-only)
- `npm ls @appium/base-driver --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @appium/base-driver.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3wgp-x9p5-c7cc (GitHub-reviewed advisory GHSA-3wgp-x9p5-c7cc lists affected ranges: npm @appium/base-driver >=0 <=10.6.0)

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