CVE-2026-84170
HighCVSS 8.3Summary
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.
Risk Assessment
An attacker can repeatedly exhaust disk (parts spooled to temp directory and the IUploadsFileManager folder) or heap (non-file parts read fully into memory) with a single repeatable request, causing denial of service. The lack of required authorization lowers the bar for exploitation.
Recommendation
Upgrade Apache Wicket to version 9.25.0 or 10.12.0. If upgrading is not possible, add your own authorization to the upload resource and enforce limits at the server/proxy level.
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-2026-84172Medium
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-2026-83594High
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)
Allocation of resources without limits or throttling in Apache Wicket. org.apache.wicket.markup.html.form.upload.resource.AbstractFileUploadResource is the server side of the form-less upload offered by FileUploadToResourceField, which posts the selected files to a separately mounted resource rather than through a Form. The resource is an application-wide singleton with no component to consult, so newResourceResponse() takes the three limits that bound the upload - the total request size, the maximum size of a single part and the maximum number of parts - from the request parameters maxSize, fileMaxSize and fileCountMax, and hands them to the multipart parser as they arrive. Nothing binds those numbers to the field that is supposed to be uploading. A request naming a very large maxSize is therefore parsed with no effective ceiling on the total size, and omitting fileMaxSize and fileCountMax leaves the per-part and part-count limits unset as well. The values the application configured through FileUploadToResourceField#setMaxSize(), #setFileMaxSize() and #setFileCountMax() are consulted only when the client omits the corresponding parameter, so against a client that supplies one they have no effect at all. Parts above the parser's in-memory threshold are spooled to the container's temporary directory, and the file parts are then copied into the folder the application's IUploadsFileManager owns, under a sub-folder the request names, where they remain. A part that is not a file is read into the heap in full while the request is parsed. One request, repeatable, can therefore consume as much disk or as much heap as the client chooses to send. The resource carries no authorization annotation and the default authorization strategy permits every resource request, so unless the application authorizes the resource itself the request needs no authentication, no session, no prior page view and no user interaction. An application is affected where it uses FileUploadToResourceField, or mounts FileUploadResourceReference itself. This is not the ordinary upload path: the resource is a singleton that has to be created and mounted deliberately. An application that configures no upload limit at all loses nothing, because Wicket applies no total-size limit of its own by default; what the defect removes is a limit the application set. Uploads through Form with FileUploadField, and through AjaxFileDropBehavior, are not affected, because both read their limits from the component rather than from the request. The upload resource does not exist in the 8.x line. This issue affects Apache Wicket: from 9.14.0 through 9.24.0, from 10.0.0 through 10.9.1. Users are recommended to upgrade to version 9.25.0 or 10.12.0, which fix the issue.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS