{"schema":"threatline.record/2","record":{"id":"CVE-2026-104798","aliases":[],"summary":"My Calendar <= 3.8.7 - Unauthenticated Privilege Escalation to 'mcs' Parameter via Reflected Shortcode Injection into 'above' Attribute","details":"The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 3.8.7. The public `mcs` GET parameter is reflected into post content unsanitized before WordPress core's `do_shortcode` filter runs, allowing an unauthenticated attacker to inject a nested `[my_calendar above=...]` shortcode; `mc_generate_calendar_nav()` then splits the `above` attribute on commas and dispatches each element via `call_user_func()` with no authentication, authorization, or callable allowlist check. This makes it possible for unauthenticated attackers to invoke arbitrary loaded PHP functions, enabling a call chain in which the shortcode `$params` array is passed to `edit_user()` — which PHP coerces to integer `1` as the `$user_id` argument — overwriting the credentials of the initial Administrator account (user ID 1) and granting the attacker full wp-admin access. Exploitation is trivially reachable via the plugin's auto-generated `/my-calendar/` page, which is publicly accessible by default upon plugin activation.","categories":["Unclassified"],"product":"My Calendar – Accessible Event Manager","vendor":"joedolson","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-104798","source_modified_at":"2026-10-16T17:07:17.621Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"My Calendar – Accessible Event Manager","vendor":"joedolson","versions":[{"version":"0","status":"affected","lessThanOrEqual":"3.4.24","versionType":"semver"},{"version":"3.5","status":"affected","lessThanOrEqual":"3.5.21","versionType":"semver"},{"version":"3.6","status":"affected","lessThanOrEqual":"3.6.17","versionType":"semver"},{"version":"3.7","status":"affected","lessThanOrEqual":"3.7.17","versionType":"semver"},{"version":"3.8","status":"affected","lessThanOrEqual":"3.8.7","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":9.8,"severity":"Critical","kev":{"listed":false},"epss":{"probability":0.00891,"percentile":0.5902,"score_date":"2026-10-23"},"published_at":"2026-10-16T04:27:04.876Z","modified_at":"2026-10-16T17:07:17.621Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-104798","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-16T17:07:17.621Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-104798","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/e8aa6ee7-525e-4458-9f5b-1e729afe448c?source=cve"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-navigation.php#L248"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-navigation.php#L260"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-search.php#L221"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-search.php#L170"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-shortcodes.php#L102"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.6/my-calendar-output.php#L1622"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/changeset?reponame=&old=3746389%40my-calendar&new=3746389%40my-calendar"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"total","assessed_at":"2026-10-16T16:48:56.803700Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-16T17:07:17.621Z","content_hash":"ee825912e8e53ccbce34e9ff1033f310eb3c5d32756e200f236d2e2c80fceb58"}}