# CVE-2026-48951: Joomla! CMS XSS in modalreturn layouts

Source: https://junglewise.ai/threats/cve-2026-48951-joomla-cms-xss-in-modalreturn-layouts  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07. Updated: 2026-07-07  
License: CC BY 4.0 with a link back

CVE-2026-48951 · Severity: info · CVSS 5.9 · Published 2026-07-07

Joomla! CMS is a popular platform used to build and manage websites. A security flaw in how the system handles certain pop-up window layouts could allow an attacker to inject malicious scripts. If successful, this could lead to unauthorized actions being performed in the context of an administrator's session, potentially compromising the website's integrity or data.

## Quick answers

**Is CVE-2026-48951 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48951 being exploited in the wild.

**How severe is CVE-2026-48951?** Informational severity, with a CVSS score of 5.9, published 7 July 2026.

**Which products and versions are affected?** Joomla! Project Joomla! CMS 4.0.0 - 5.4.6, 6.0.0 - 6.1.1.

**Is there a fix for CVE-2026-48951?** A patch was published on 2026-07-07: Fixed in versions 5.4.7 and 6.1.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48951 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-48951?** 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

A stored cross-site scripting (XSS) vulnerability exists in Joomla! CMS versions 4.0.0 through 5.4.6 and 6.0.0 through 6.1.1. The issue stems from a lack of proper output escaping within the 'modalreturn' layouts used by various core components. An attacker with high-privileged access (PR:H) could exploit this by injecting malicious scripts that execute when a user interacts with the affected modal interface. This could lead to session hijacking or unauthorized administrative actions. The vulnerability is addressed in versions 5.4.7 and 6.1.2.

## Affected products

- Joomla! Project Joomla! CMS 4.0.0 - 5.4.6, 6.0.0 - 6.1.1

## Timeline

- 2026-05-07: other: Reported date
- 2026-07-07: patched: Fixed in versions 5.4.7 and 6.1.2
- 2026-07-07: disclosed: NVD publication date

## References

- [https://developer.joomla.org/security-centre/1059-20260705-core-xss-in-various-modalreturn-layouts.html](https://developer.joomla.org/security-centre/1059-20260705-core-xss-in-various-modalreturn-layouts.html)