CVE-2026-84177
MediumCVSS 6.3Summary
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).
Risk Assessment
An attacker can read the HTML template content of application components, exposing component structure, developer comments, conditionally rendered markup, inline scripts and endpoint names. No user data, credentials or session material is reachable, and access is read-only.
Recommendation
Upgrade Apache Wicket to version 8.20.0, 9.25.0 or 10.12.0. 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-2026-84172Medium
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.
- 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)
Incorrect behavior order in Apache Wicket: a file path is validated before the framework appends the attributes that complete it. org.apache.wicket.request.resource.PackageResource asks the configured package resource guard about a path built from the scope class' package and the file name in the request URL, and then hands that same path to the resource stream locator together with a style, a variation and a locale. Those three attributes are decoded from the name of the first query parameter and never appear in the string the guard was given. org.apache.wicket.core.util.resource.locator.ResourceNameIterator appends them to that path, each preceded by an underscore, in the order variation, style, locale, before the file extension, so the file that is opened is not the file the guard approved. org.apache.wicket.markup.html.PackageResourceGuard decides whether an HTML file is a component's markup template by looking for a class file of the same name beside it, stripping one underscore-delimited suffix at a time as it goes. HTML is on the default allow list, so that check is the only thing separating a static HTML file, which may be served, from a markup template, which may not. Asked about the name of a template, the guard refuses it correctly. Asked about a shorter name for which no class exists, it accepts, and a style supplied in the URL then completes that name into the markup template of a component class, which is written to the response. An application is affected if the simple name of any of its component classes contains an underscore and no shorter part of that name is itself a class, such as Report_v2 or Wizard_Step1; an application with no such class name is not affected. No unusual deployment, packaging or configuration is required, and running in deployment rather than development mode does not prevent it. Java naming conventions discourage underscores in class names and no module Wicket ships has one, so no framework markup is exposed; what an application exposes this way is its own. A component whose class name has no underscore is not reachable, and neither is its localized or styled markup, because the guard finds the class file under the base name and refuses the request. The attributes cannot change the file extension and cannot leave the component's package, so nothing beyond HTML files in that package is reachable. Access is read-only, and 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. No user data, credential or session material is reachable this way. An attacker has to name a class in the target package and the component itself, 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