CVE-2021-24927
My Calendar < 3.2.18 - Subscriber+ Reflected Cross-Site Scripting
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue
- Record
CVE-2021-24927- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
My Calendar < 3.2.18 - Subscriber+ Reflected Cross-Site Scripting
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue
- Record
CVE-2021-24927- Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-11839 No score
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue
- Record
EUVD-2021-11839- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gcvg-gpgp-f6cf No score
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback...
The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue
- Record
GHSA-gcvg-gpgp-f6cf- Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-24927 is a medium vulnerability (CVSS 5.4) in Joe Dolson My Calendar, published November 29, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. No source names a fixed version.