# CVE-2026-88853: Regular Labs Modals Pro stored XSS via event handler

Source: https://junglewise.ai/threats/cve-2026-88853-regular-labs-modals-pro-stored-xss-via-event-handler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-14. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-88853 · Severity: info · CVSS 6.3 · Published 2026-09-14

Modals Pro is a Joomla extension that enables administrators to create modal popup windows on websites. A privilege-escalation vulnerability allows lower-privileged authors to inject malicious JavaScript code through event handler options that should only be available to trusted administrators, enabling them to execute arbitrary scripts when users interact with modals.

Vendors: [Regular Labs](https://junglewise.ai/threats/vendors/regular-labs).

## Quick answers

**Is CVE-2026-88853 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-88853 being exploited in the wild.

**How severe is CVE-2026-88853?** Informational severity, with a CVSS score of 6.3, published 14 September 2026.

**Which products and versions are affected?** Regular Labs Modals Pro < 17.0.0.

**Is there a fix for CVE-2026-88853?** 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-2026-88853 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-88853?** Check whether you run Regular Labs Modals Pro 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 cross-site scripting (XSS) flaw in Modals Pro for Joomla. The extension intentionally supports JavaScript event handlers (such as on-open and on-closed) for modal popups, but fails to restrict their use to trusted administrators. Lower-privileged content authors can inject malicious JavaScript through article content and event handler fields, which is then stored and executed in the browsers of site visitors. The root cause is insufficient privilege checking: the extension does not distinguish between trusted extension configuration and user-supplied event code. An authenticated author with normal article-posting permissions can exploit this without requiring additional user interaction. The impact allows arbitrary JavaScript execution in the context of the website, potentially leading to session hijacking, credential theft, or further compromise. Versions below 17.0.0 are affected.

## Affected products

- Regular Labs Modals Pro < 17.0.0

## Timeline

- 2026-09-14: disclosed: CVE-2026-88853 published
- 2026-09-14: advisory: NVD advisory released

## References

- [https://www.regularlabs.com/](https://www.regularlabs.com/)

## Related threats

- [Regular Labs Modals Pro path traversal in gallery paths](https://junglewise.ai/threats/cve-2026-65713-regular-labs-modals-pro-path-traversal-in-gallery-paths)