Login Request a demo
Medium severity · published Sep 9, 2026
CVE-2026-77187
My Calendar <= 3.8.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes
6.4
CVSS
0.3%
EPSS
No
On KEV
Description
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes 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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 26% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
My Calendar – Accessible Event Manager · joedolson
through 3.8.3 · source: vendor
Affected product
MC
My Calendar – Accessible Event Manager
joedolson
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77187
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77187
github.com
https://github.com/joedolson/my-calendar/commit/89bbf7314fac84cdb89e520e8b7b6d69eee8dd3c
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar-events.php#L1102
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar-shortcodes.php#L358
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar.php#L563
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/8c8beca2-d02b-4379-99e9-8090ef84ca6d?source=cve
More from My Calendar – Accessible Event Manager
9.8
CVE-2026-104798
My Calendar <= 3.8.7 - Unauthenticated Privilege Escalation to 'mcs' Parameter via Reflected Shortcode Injection into 'above' Attribute
7.5
CVE-2026-6854
My Calendar <= 3.7.8 - Unauthenticated SQL Injection via 'mc_auth' and 'mc_host' Parameters
6.4
CVE-2026-77186
My Calendar <= 3.8.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'fallback' Shortcode Attribute
6.4
CVE-2026-2355
My Calendar – Accessible Event Manager <= 3.7.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
5.3
CVE-2026-11896
My Calendar <= 3.7.14 - Insecure Direct Object Reference to Unauthenticated Sensitive Information Disclosure via 'vcal' Parameter