How severe is CVE-2020-6506?

CVE-2020-6506 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-6506?

CVE-2020-6506 affects the following packages: react-native-webview (npm). Ecosystems affected: npm.

How do I fix CVE-2020-6506?

Update react-native-webview to 11.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-6506 is resolved across your whole dependency graph.

How do I detect CVE-2020-6506 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-native-webview. 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.

How do I mitigate CVE-2020-6506 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2020-6506?

O3 pinpoints whether CVE-2020-6506 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2020-6506 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-6506 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2020-6506 published, and has it been updated?

CVE-2020-6506 was published on July 22, 2020 and was last updated on March 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2020-6506

MEDIUM

CVE-2020-6506 is a medium-severity (CVSS 6.5) vulnerability in react-native-webview. O3 Security confirms whether CVE-2020-6506 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Android WebView Universal Cross-site Scripting

Also known asGHSA-36j3-xxf7-4pqg

Published

Jul 22, 2020

Updated

Mar 15, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Mar 15, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

1Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

react-native-webviewnpm

4.5Mdownloads / week

Description

Insufficient policy enforcement in WebView in Google Chrome on Android prior to 83.0.4103.106 allowed a remote attacker to bypass site isolation via a crafted HTML page.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`react-native-webview`	all versions	11.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-native-webview. 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 react-native-webview to 11.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-6506 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-2020-6506 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-2020-6506. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

RHSA-2020:2643Red Hat Enterprise Linux 6 Supplementary

Frequently Asked Questions

Insufficient policy enforcement in WebView in Google Chrome on Android prior to 83.0.4103.106 allowed a remote attacker to bypass site isolation via a crafted HTML page.

O3 Security · Impact-Aware SCA

Is CVE-2020-6506 in your dependencies?

O3 detects CVE-2020-6506 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works