CVE-2026-84172
MediumCVSS 6.3Summary
In Apache Wicket, PackageResourceGuard incorrectly allows component markup templates to be served as package resources when wicket-core is loaded by a class loader that cannot see the application's classes. In such a setup the check for a class file beside the template fails, and a request for the package resource URL returns the component's markup template with status 200. Disclosed content is developer-authored template material such as component structure, comments, inline script, and named endpoints.
Risk Assessment
The risk applies only to unusual deployments where wicket-core is in a separate class loader (e.g. a container shared library directory, an EAR library directory, an application server global module, or an OSGi bundle). Standard deployments with wicket-core in WEB-INF/lib are not affected. Access is read-only and does not expose user data, credentials, or session material.
Recommendation
Upgrade Apache Wicket to version 8.20.0, 9.25.0, or 10.12.0, which fix the issue. Users of Wicket 7.x or older should upgrade to a supported version.
Other vulnerabilities in Apache Wicket
See all- CVE-2026-95863High
Apache Wicket generates JavaScript that references rendered elements, placing markup ids and form input names inside single-quoted JavaScript string literals without proper escaping. A value containing a single quote or backslash can terminate the literal and inject script that runs in the application's origin when the page loads. The issue affects wicket-core and wicket-extensions in versions 8.0.0 through 8.19.0, 9.0.0 through 9.24.0, and 10.0.0 through 10.11.0.
- CVE-2026-87718Low
Apache Wicket 10.10.0, 10.11.0 and 9.24.0 do not set Content-Security-Policy headers on a page whose render request handler is wrapped in more than one IRequestHandlerDelegate. The framework unwraps only a single delegate level when deciding whether a request renders a page, so with a deeper chain, for example an application-provided delegating request mapper combined with CryptoMapper, the page is served without any CSP header even though CSP is enabled, and no error or warning is raised. The nonce-based protection Wicket applies to inline scripts and styles, together with any other CSP directives configured by the application, is thereby lost for those pages, exposing them to content injection the policy was meant to prevent. Applications on stock Wicket that do not wrap request handlers themselves are not affected. Versions before 10.10.0 and 9.24.0 handled nested delegates correctly.
- CVE-2026-84231High
A cross-site scripting (XSS) vulnerability in Apache Wicket arises from improper neutralization of input during web page generation. The ExternalLink component, when bound to a non-anchor element, concatenates the model URL into a JavaScript string literal in the onclick attribute without proper escaping, allowing script execution in the application's origin.
- CVE-2026-84177Medium
Apache Wicket has an incorrect behavior order: a file path is validated by PackageResourceGuard before the framework appends the style, variation and locale attributes. As a result, the file opened may differ from the file approved by the guard, allowing disclosure of HTML markup templates of components whose class names contain an underscore (e.g. Report_v2).
- CVE-2026-84170High
A vulnerability in Apache Wicket affects AbstractFileUploadResource, the server side of the form-less upload offered by FileUploadToResourceField. The request size, single-part size and part-count limits are taken from request parameters (maxSize, fileMaxSize, fileCountMax) instead of application configuration, so a client can raise or omit them. The resource carries no authorization annotation, so by default requests need no authentication.
- CVE-2026-83594High
A vulnerability in Apache Wicket affects the FileUploadToResourceField component, whose Ajax callback reads the filesInfo request parameter without binding it to an actual upload. The UploadInfo#get() method allocates a byte array based on the client-supplied size, allowing a single request to exhaust the JVM heap, while negative values trigger a NegativeArraySizeException.
- CVE-2026-83559High
A vulnerability in Apache Wicket affects the JavaScriptUtils#escapeQuotes() method, which fails to escape the backslash character before quotes. A value containing a backslash immediately before a quote results in the quote being left unescaped, closing the JavaScript string literal and allowing JavaScript injection. The issue occurs when an application uses this method to place attacker-influenced data inside a JavaScript string literal, including via the AjaxEditableLabel component.
- CVE-2026-83539High
Cross-site scripting (XSS) vulnerability in the SmartLinkLabel and SmartLinkMultiLineLabel components of Apache Wicket. These components turn URLs found in text into hyperlinks and accept any URL scheme, including script-executing schemes such as javascript:. Escaping the model value does not help because the payload ends up in the href attribute rather than in element text.
- CVE-2026-82956High
A cross-site scripting (XSS) vulnerability in Apache Wicket affects the AjaxNewWindowNotifyingBehavior, which stores the client-supplied window.name value in the page's serialized state. That value is later substituted without escaping into a single-quoted JavaScript string literal in the Ajax call precondition, allowing arbitrary script execution in the application's origin on every render of the page instance. Only applications that explicitly add this behavior to a component are affected.
- CVE-2026-111089High
Apache Wicket writes texts from resource bundles (labels, CSS class names) into generated JavaScript and markup without context-appropriate escaping. A text containing a quote can terminate the literal or attribute and be parsed as script or markup in the application's origin. Affected components include MultiFileUploadField, Form, UploadProgressBar, FilterForm and TrapFocusBehavior in versions 8.0.0–8.19.0, 9.0.0–9.24.0 and 10.0.0–10.11.0.
Original NVD description (English source)
Files accessible to external parties in Apache Wicket. org.apache.wicket.markup.html.PackageResourceGuard decides whether a file on the classpath may be streamed to a client as a package resource. HTML is on the default allow list, so the only thing that separates a static HTML file, which may be served, from a component's markup template, which may not, is a check for a class file of the same name beside it. That check calls getResource() on the class loader that loaded wicket-core. The resource itself is reached through different class loaders: the scope class is resolved through the application's IClassResolver, which uses the thread context class loader, and org.apache.wicket.core.util.resource.ClassPathResourceFinder#find() then tries the scope class' own loader, the context class loader, and the wicket-core loader last. Where wicket-core is loaded by a class loader that cannot see the application's classes, the check finds no class file, concludes the file is not a component markup template, and serves it. A request for the package resource URL of a component class then returns that component's markup template with status 200. What is disclosed is developer-authored template content: component structure, developer comments, markup that is rendered only under some conditions, inline script, and the endpoints a template names. Access is read-only, and no user data, credential or session material is reachable this way. Such a deployment is rare. The ordinary packaging, a web archive with wicket-core in WEB-INF/lib, puts the framework and the application in one class loader, so the check finds the class file and the template is refused; those deployments are not affected. The exposure is confined to deployments that give wicket-core a class loader which cannot see the application's component classes: wicket-core placed in a servlet container's shared library directory, in an enterprise archive library directory with the application in the web archive, as an application server global module, or as an OSGi bundle, where wicket-core's bundle cannot resolve a class held by an application bundle. Markup shipped by Wicket's own modules, and by any other code sharing a class loader with wicket-core, remains protected. An attacker has to name a component class, and Wicket writes fully qualified class names into the URL of every package resource it renders. This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS