CVE-2026-58191
MEDIUMCVE-2026-58191 is a medium-severity (CVSS 6.5) Cross-site Scripting (XSS) vulnerability in @appium/base-driver. O3 Security confirms whether CVE-2026-58191 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Appium: Reflected XSS / arbitrary JS in @appium/base-driver /test/guinea-pig* routes
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-58191 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 367,327 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
@appium/base-driverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Appium is a cross-platform automation framework for all kinds of apps, built on top of the W3C WebDriver protocol. Prior to 10.7.0, Appium's base-driver unconditionally mounts the /test/guinea-pig, /test/guinea-pig-scrollable, and /test/guinea-pig-app-banner routes, and compileLodashTemplate reflects the throwError query parameter, comments POST field, and User-Agent request header into HTML without escaping, allowing reflected cross-site scripting and arbitrary JavaScript execution on the server origin. This issue is fixed in version 10.7.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @appium/base-driver | all versions | 10.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @appium/base-driver. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @appium/base-driver to 10.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58191 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-58191 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-58191. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-58191 in your dependencies?
O3 detects CVE-2026-58191 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.