Is CVE-2026-77187 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-77187 being exploited in the wild.

How severe is CVE-2026-77187?

Medium severity, with a CVSS score of 6.4, published 9 September 2026.

Which products and versions are affected?

Joe Dolson My Calendar – Accessible Event Manager up to and including 3.8.3.

Is there a fix for CVE-2026-77187?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-77187 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-77187?

Check whether you run Joe Dolson My Calendar – Accessible Event Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-77187: WordPress My Calendar Stored XSS in shortcode attributes

CVE-2026-77187 · Severity: medium · CVSS 6.4 · Published 2026-09-09

My Calendar is a popular WordPress plugin for managing and displaying events on websites. The plugin is vulnerable to stored cross-site scripting (XSS), which allows attackers with contributor-level access to inject malicious scripts into event pages. When other users view these pages, the injected scripts execute, potentially stealing credentials, defacing content, or compromising visitor data.

Vendors: Joe Dolson.

Quick answers

Is CVE-2026-77187 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-77187 being exploited in the wild.
How severe is CVE-2026-77187?: Medium severity, with a CVSS score of 6.4, published 9 September 2026.
Which products and versions are affected?: Joe Dolson My Calendar – Accessible Event Manager up to and including 3.8.3.
Is there a fix for CVE-2026-77187?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-77187 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-77187?: Check whether you run Joe Dolson My Calendar – Accessible Event Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a Stored XSS flaw in the 'before' and 'after' shortcode attributes of the My Calendar plugin. The root cause is insufficient input sanitization and output escaping when processing these shortcode parameters. An authenticated attacker with contributor-level access or higher can inject arbitrary JavaScript into shortcode attributes, which is stored in the database and executed in the browsers of all users who view the affected pages. The vulnerability affects all versions up to and including 3.8.3. Patches are available in later versions as evidenced by sanitization commits in the plugin repository.

Affected products

Joe Dolson My Calendar – Accessible Event Manager up to and including 3.8.3

Timeline

2026-09-09: disclosed

References

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