Quick answers
- Is CVE-2026-77991 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77991 being exploited in the wild.
- How severe is CVE-2026-77991?
- Informational severity, with a CVSS score of 8.8, published 27 August 2026.
- Which products and versions are affected?
- Joomlaeventmanager.Net Joomla Event Manager < 5.0.1.
- Is there a fix for CVE-2026-77991?
- 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-2026-77991 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-77991?
- Check whether you run Joomlaeventmanager.Net Joomla 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 exists in the administrator source model component of Joomla Event Manager, which insufficiently validates file types during upload operations. An authenticated administrator can upload malicious PHP files or other dangerous file types that bypass file-type restrictions, resulting in arbitrary code execution on the server. The attack requires administrator privileges and access to the backend interface. This issue was addressed in version 5.0.1. The vulnerability class is improper file upload validation leading to remote code execution.
Affected products
- JoomlaEventManager.net Joomla Event Manager < 5.0.1
Timeline
- 2026-08-27: disclosed