Is CVE-2026-77990 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-77990 being exploited in the wild.

How severe is CVE-2026-77990?

Informational severity, published 27 August 2026.

Which products and versions are affected?

Joomla Event Manager Joomla Event Manager < 5.0.1.

Is there a fix for CVE-2026-77990?

A patch was published on 2026-09-14: JEM 5.0.1 released with granular backend ACL Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-77990 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-77990?

Check whether anything you run is named in the advisory. 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-2026-77990: Joomla Event Manager attendee list unauthorized disclosure

Q: Is there a fix for CVE-2026-77990?

A patch was published on 2026-09-14: JEM 5.0.1 released with granular backend ACL Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-77990 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-77990?

Check whether anything you run is named in the advisory. 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-2026-77990 · Severity: info · Published 2026-08-27

Joomla Event Manager is a free extension for Joomla that manages events, registrations, and attendee information. In versions before 5.0.1, any logged-in user (not just event managers) could read attendee lists for events they do not manage, exposing names, usernames, registration dates, and participation statuses—including for unpublished events. This represents a privacy breach where sensitive attendee data intended for event organizers becomes visible to unauthorized users.

Quick answers

Is CVE-2026-77990 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-77990 being exploited in the wild.
How severe is CVE-2026-77990?: Informational severity, published 27 August 2026.
Which products and versions are affected?: Joomla Event Manager Joomla Event Manager < 5.0.1.
Is there a fix for CVE-2026-77990?: A patch was published on 2026-09-14: JEM 5.0.1 released with granular backend ACL Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-77990 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-77990?: Check whether anything you run is named in the advisory. 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 an improper access control flaw in Joomla Event Manager's attendee list functionality. The extension fails to properly enforce role-based authorization (ACL), allowing any authenticated user to view attendee lists regardless of their event-management permissions. The attack vector is network-based and requires only valid Joomla user credentials; no elevation of privileges or social engineering is necessary. An authenticated attacker can enumerate attendee data, registration details, and event participation status for events they have no legitimate access to. The vulnerability is fixed in version 5.0.1, which implements granular backend ACL for events, venues, and attendees.

Affected products

Joomla Event Manager Joomla Event Manager < 5.0.1

Timeline

2026-08-27: disclosed
2026-09-14: patched: JEM 5.0.1 released with granular backend ACL

References

https://www.joomlaeventmanager.net/

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