HighCVE-2026-84170

    Apache Wicket: Configured upload limits are not enforced by the standalone file upload resource (CVE-2026-84170)

    Published Last modified Sources: CVE.org, BSI

    What is affected, what to do

    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.

    Update Wicket to version 9.25.0.

    Affected
    • Apache Wicket lte 9.14.0..9.24.0
    • Apache Wicket lte 10.0.0..10.9.1

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    Metrics

    8.3

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v4

    8.3

    CVSS v4

    Severity High on the scale from 0 to 10.

    Source: CVE.org, BSI

    —

    EPSS score

    No value is available for this vulnerability.

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    71.50 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

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    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.3 Methodology
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.3
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-770

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    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.

    Source: NVD (NIST), cvelistv5, BSI CSAF, BSI WID Portal

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    Apache Software FoundationApache Wicket
    • 9.14.0 – ≤ 9.24.0
    • 10.0.0 – ≤ 10.9.1
    • —
    • —
    ApacheWicket
    • < 9.25.0
    • < 10.12.0
    • < 8.20.0
    • 9.25.0
    • 10.12.0
    • 8.20.0

    Vendors and products

    Weakness classes (CWE)

    • CWE-770Allocation of Resources Without Limits or Throttling

      Base

      The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

      Entry at MITRE CWE-770

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. ReceivedApache

      CVSS V4.0: AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

      Weakness type: CWE-770

      Description added or changed

      Show 5 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      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.
      CVSSadded
      —
      AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      Weakness type (CWE)added
      —
      CWE-770
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84170.json">CVE-2026-84170</a>
      Referenceadded
      —
      https://lists.apache.org/thread.html/bw3hn5cch3q7yrsl05m8mvmgyx4m98y7

      Source identifier: security@apache.org

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