# CVE-2026-78077: JoomShaper Helix Ultimate stored XSS in MegaMenu layout

Source: https://junglewise.ai/threats/cve-2026-78077-joomshaper-helix-ultimate-stored-xss-in-megamenu-layout  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-31. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-78077 · Severity: info · Published 2026-08-31

Helix Ultimate is a free Joomla template widely used to build websites. An attacker with template editing access could inject malicious code into the MegaMenu layout configuration that would execute in the browsers of site administrators and visitors, potentially allowing account takeover, data theft, or site defacement.

Technologies: [JoomShaper Helix Ultimate](https://junglewise.ai/threats/technologies/helix-ultimate). Vendors: [JoomShaper](https://junglewise.ai/threats/vendors/joomshaper).

## Quick answers

**Is CVE-2026-78077 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78077 being exploited in the wild.

**How severe is CVE-2026-78077?** Informational severity, published 31 August 2026.

**Which products and versions are affected?** JoomShaper Helix Ultimate < 2.2.10.

**Is there a fix for CVE-2026-78077?** 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-2026-78077 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-78077?** Check whether you run JoomShaper Helix Ultimate 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 the MegaMenu component of Helix Ultimate. Unsanitized column and item configuration values stored in the MegaMenu layout JSON are rendered without complete contextual HTML escaping, allowing injection of arbitrary HTML and JavaScript. An attacker with write access to template configuration can craft malicious payloads that persist in the template data and execute when administrators or site visitors load pages containing the MegaMenu. The fix implements stricter input sanitization and tag allowlists using Joomla's InputFilter class and htmlspecialchars() for contextual escaping. Versions prior to 2.2.10 are affected.

## Affected products

- JoomShaper Helix Ultimate < 2.2.10

## Timeline

- 2026-08-31: published: Advisory published on NVD

## References

- [https://www.joomshaper.com/joomla-templates/helixultimate](https://www.joomshaper.com/joomla-templates/helixultimate)

## Related threats

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- [JoomShaper Helix Ultimate broken access control in MegaMenu settings](https://junglewise.ai/threats/cve-2026-78076-joomshaper-helix-ultimate-broken-access-control-in-megamenu)