{"cve":"CVE-2026-77186","nvd":{"published":"2026-09-09T04:19:55.880","modified":"2026-09-09T15:33:34.467","status":"Deferred","description":"The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'fallback' Shortcode Attribute in all versions up to, and including, 3.8.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The bypass relies on hex-encoded shortcode attribute payloads (e.g. \\x3cscript\\x3e), which wp_kses_post cannot strip on save because they appear as literal backslash sequences rather than real HTML tags; WordPress core's shortcode_parse_atts() then calls stripcslashes() at render time, decoding the escapes into real angle brackets before they reach the unescaped sink.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","score":6.4},"cwes":["CWE-79"],"references":["https://github.com/joedolson/my-calendar/commit/89bbf7314fac84cdb89e520e8b7b6d69eee8dd3c","https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-shortcodes.php#L114","https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-widgets.php#L272","https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar.php#L556","https://www.wordfence.com/threat-intel/vulnerabilities/id/62c8fb1f-6cba-43cc-8aca-70812c29a63d?source=cve"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:53.108888569+00:00"},"epss":{"cve":"CVE-2026-77186","score":0.00356,"percentile":0.29323,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}