# CVE-2026-84021: Bold Page Builder stored XSS via link URL validation bypass

Source: https://junglewise.ai/threats/cve-2026-84021-bold-page-builder-stored-xss-via-link-url-validation-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-05. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-84021 · Severity: medium · CVSS 6.8 · Published 2026-09-05

The Bold Page Builder WordPress plugin used to create custom page layouts does not properly validate URLs in shortcodes, allowing contributors and above to inject malicious scripts. When a user clicks a crafted link in a published page, the malicious script executes in their browser, enabling attackers to steal session data, modify page content, or perform actions on behalf of the victim.

## Quick answers

**Is CVE-2026-84021 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-84021 being exploited in the wild.

**How severe is CVE-2026-84021?** Medium severity, with a CVSS score of 6.8, published 5 September 2026.

**Which products and versions are affected?** Bold Page Builder before 5.9.8.

**Is there a fix for CVE-2026-84021?** A patch was published on 2026-09-05: Fixed in version 5.9.8 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-84021 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-84021?** 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 a stored cross-site scripting (XSS) flaw in the bt_bb_button, bt_bb_headline, and bt_bb_icon shortcode handlers. The plugin relies on a filter to validate link URLs before output in HTML attributes, but the filter can be evaded by embedding a literal tab character (0x09) between the JavaScript protocol scheme and the script keyword (e.g., java[TAB]script:). The browser's URL parser strips the tab during parsing, reassembling the javascript: scheme and executing the injected code. Attack requires Contributor role or above; no special configuration is needed. The vulnerability is fixed in version 5.9.8.

## Affected products

- Bold Page Builder before 5.9.8

## Timeline

- 2026-09-03: disclosed
- 2026-09-05: patched: Fixed in version 5.9.8

## References

- [https://wpscan.com/vulnerability/ca226eab-59a2-42d5-96f6-84dacf7c6c5a/](https://wpscan.com/vulnerability/ca226eab-59a2-42d5-96f6-84dacf7c6c5a/)