CVE-2026-77187
My Calendar <= 3.8.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.4
My Calendar <= 3.8.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes
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.
- Record
CVE-2026-77187- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-74604
6.4
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.
- Record
EUVD-2026-74604- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qr78-jfh8-8x2x
6.4
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross...
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.
- Record
GHSA-qr78-jfh8-8x2x- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
6.4
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.
- Record
CVE-2026-77187- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
6.4
My Calendar <= 3.8.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes
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.
- Record
CVE-2026-77187- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-77187 is a medium vulnerability (CVSS 6.4) in Joedolson My Calendar – Accessible Event Manager, published September 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 26th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/8c8beca2-d02b-4379-99e9-8090ef84ca6d?source=cve
plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar-events.php
plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar-shortcodes.php
plugins.trac.wordpress.org/browser/my-calendar/tags/3.8.0/my-calendar.php
github.com/joedolson/my-calendar/commit/89bbf7314fac84cdb89e520e8b7b6d69eee8dd3c
nvd.nist.gov/vuln/detail/CVE-2026-77187
github.com/advisories/GHSA-qr78-jfh8-8x2x
github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77187.json