CVE intelligence and bounded remediation

CVE-2020-9459 — Webnus Modern Events Calendar Lite security vulnerability

Medium CVSS 5.4

Multiple Stored Cross-site scripting (XSS) vulnerabilities in the Webnus Modern Events Calendar Lite plugin through 5.1.6 for WordPress allows remote authenticated users (with minimal permissions) to inject arbitrary JavaScript, HTML, or CSS via Ajax actions. This affects mec_save_notifications and import_settings.

Severity
Medium
CVSS
5.4 (3.1)
Published
2020-02-28
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • webnus / modern_events_calendar_lite

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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