6.4
MEDIUM CVSS 3.1
CVE-2026-2355
My Calendar – Accessible Event Manager <= 3.7.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
Description

The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `template` attribute of the `[my_calendar_upcoming]` shortcode in all versions up to, and including, 3.7.3. This is due to the use of `stripcslashes()` on user-supplied shortcode attribute values in the `mc_draw_template()` function, which decodes C-style hex escape sequences (e.g., `\x3c` to `<`) at render time, bypassing WordPress's `wp_kses_post()` content sanitization that runs at save time. 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.

INFO

Published Date :

March 4, 2026, 12:16 p.m.

Last Modified :

March 4, 2026, 12:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-2355 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update the My Calendar plugin to patch a stored Cross-Site Scripting vulnerability.
  • Update the My Calendar plugin to version 3.7.4 or later.
  • Remove any previously injected malicious scripts.
  • Verify that user input is properly sanitized.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-2355 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-2355 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-2355 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-2355 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 04, 2026

    Action Type Old Value New Value
    Added Description The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `template` attribute of the `[my_calendar_upcoming]` shortcode in all versions up to, and including, 3.7.3. This is due to the use of `stripcslashes()` on user-supplied shortcode attribute values in the `mc_draw_template()` function, which decodes C-style hex escape sequences (e.g., `\x3c` to `<`) at render time, bypassing WordPress's `wp_kses_post()` content sanitization that runs at save time. 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Reference https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.7.2/my-calendar-shortcodes.php#L112
    Added Reference https://plugins.trac.wordpress.org/browser/my-calendar/tags/3.7.2/my-calendar-templates.php#L83
    Added Reference https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-shortcodes.php#L112
    Added Reference https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-templates.php#L83
    Added Reference https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3464603%40my-calendar%2Ftrunk&old=3454989%40my-calendar%2Ftrunk&sfp_email=&sfph_mail=#file6
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/03d5c82e-f82f-4156-bb3e-e6eb365a6c36?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 6.4
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact