# CVE-2026-83539: Apache Wicket XSS in SmartLinkLabel

Source: https://junglewise.ai/threats/cve-2026-83539-improper-neutralization-of-input-during-web-page-generation-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-01. Updated: 2026-11-01  
License: CC BY 4.0 with a link back

CVE-2026-83539 · Severity: info · Published 2026-11-01

Apache Wicket is a web application framework that renders user-supplied text and automatically converts URLs it finds into clickable links. The SmartLinkLabel and SmartLinkMultiLineLabel components accept any URL scheme when linkifying text, allowing an attacker to inject links with schemes like "javascript:" that execute code when clicked. Users viewing a page containing such a malicious link will have the script run in their browser session within the application's origin.

Technologies: [Apache Wicket](https://junglewise.ai/threats/technologies/apache-wicket). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-83539 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83539 being exploited in the wild.

**How severe is CVE-2026-83539?** Informational severity, published 1 November 2026.

**Which products and versions are affected?** Apache Wicket 8.0.0 through 8.19.0, 9.0.0 through 9.24.0, 10.0.0 through 10.11.0.

**Is there a fix for CVE-2026-83539?** Yes: fixed in Wicket 8.20.0, 9.25.0, 10.12.0. Until then: On Wicket 9.x and 10.x, ensure the default Content-Security-Policy with nonce-based script allowance remains enabled and is not weakened. Applications unable to upgrade should avoid rendering untrusted text through SmartLinkLabel or SmartLinkMultiLineLabel components. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-83539 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-83539?** Check whether you run Apache Wicket 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.

## How to fix

- Fixed in Wicket 8.20.0, 9.25.0, 10.12.0

On Wicket 9.x and 10.x, ensure the default Content-Security-Policy with nonce-based script allowance remains enabled and is not weakened. Applications unable to upgrade should avoid rendering untrusted text through SmartLinkLabel or SmartLinkMultiLineLabel components.

## Technical details

The SmartLinkLabel and SmartLinkMultiLineLabel components escape model values but then pass them to DefaultLinkParser, which matches any scheme://rest pattern and wraps matches in anchors without validating the scheme. An attacker can inject javascript: or other executable schemes; the text escaping does not prevent this because the payload resides in the href attribute (a URL context) rather than element text. On Wicket 9.x and 10.x, the default Content-Security-Policy with nonce-based script allowance mitigates this, but Wicket 8.x has no CSP support, and applications with weakened CSP policies remain vulnerable.

## Affected products

- Apache Wicket 8.0.0 through 8.19.0, 9.0.0 through 9.24.0, 10.0.0 through 10.11.0

## Timeline

- 2026-11-01: disclosed
- 2026-11-01: advisory

## Related threats

- [Apache Wicket improper input neutralization in JavaScript generation](https://junglewise.ai/threats/cve-2026-95863-improper-neutralization-of-input-during-web-page-generation-in)
- [Apache Wicket missing Content-Security-Policy headers with nested request handler delegates](https://junglewise.ai/threats/cve-2026-87718-apache-wicket-10-10-0-10-11-0-and-9-24-0-do-not-set-the-content)
- [Apache Wicket ExternalLink reflected XSS in onclick attribute](https://junglewise.ai/threats/cve-2026-84231-improper-neutralization-of-input-during-web-page-generation-in)
- [Apache Wicket path validation bypass in package resource handling](https://junglewise.ai/threats/cve-2026-84177-incorrect-behavior-order-in-apache-wicket-a-file-path-is)
- [Apache Wicket template disclosure via class loader misconfiguration](https://junglewise.ai/threats/cve-2026-84172-files-accessible-to-external-parties-in-apache-wicket-org-apache)