CVE-2026-84172: Apache Wicket template disclosure via class loader misconfiguration

CVE-2026-84172 · Severity: info · Published 2026-11-01

Apache Wicket is a Java web framework that serves static resources like HTML templates to clients. In certain deployment configurations where the framework is isolated in a separate class loader from the application, an attacker can request a component's markup template and receive its full source code. This exposes developer comments, template structure, and internal endpoint names, though no user data or credentials are at risk.

Technologies: Apache Wicket. Vendors: Apache.

Quick answers

Is CVE-2026-84172 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-84172 being exploited in the wild.
How severe is CVE-2026-84172?
Informational severity, published 1 November 2026.
Which products and versions are affected?
Apache Wicket 8.0.0–8.19.0, 9.0.0–9.24.0, 10.0.0–10.11.0.
Is there a fix for CVE-2026-84172?
Yes: fixed in Wicket 8.20.0, 9.25.0, 10.12.0. Until then: Ensure wicket-core is packaged in the application's class loader (standard WEB-INF/lib placement in a web archive) rather than in a shared servlet container library, enterprise archive library, application server global module, or separate OSGi bundle.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-11-01"}] Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-84172 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-84172?
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

Ensure wicket-core is packaged in the application's class loader (standard WEB-INF/lib placement in a web archive) rather than in a shared servlet container library, enterprise archive library, application server global module, or separate OSGi bundle.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-11-01"}]

Technical details

PackageResourceGuard in Apache Wicket checks whether a file may be served as a package resource by verifying a corresponding class file exists, preventing disclosure of component markup templates. When wicket-core is in a separate class loader from the application (e.g., in a shared library, OSGi bundle, or enterprise archive), the check fails to find the class file and incorrectly authorizes template delivery. An attacker can construct a package resource URL using fully qualified class names extracted from rendered URLs to retrieve template source code.

Affected products

  • Apache Wicket 8.0.0–8.19.0, 9.0.0–9.24.0, 10.0.0–10.11.0

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