CVE-2026-1047989.8CriticalCWE-269

CVE-2026-104798: My Calendar <= 3.8.7 - Unauthenticated Privilege Escalation to 'mcs' Parameter via Reflected Shortcode Injection into 'above' Attribute

joedolson · My Calendar – Accessible Event Manager

Affected: joedolson My Calendar – Accessible Event Manager · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

41st percentile

050100

Higher than 41% of scored CVEs

9.8CriticalCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

joedolson · My Calendar – Accessible Event Managerup to and including 3.4.24; from 3.5 up to and including 3.5.21; from 3.6 up to and including 3.6.17; from 3.7 up to and including 3.7.17; from 3.8 up to and including 3.8.7

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improper Privilege Management · Access Control
Vendor: joedolson
Published: October 2026
Band: Unlikely (under 1%), October 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-104798 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.