Apache Wicket: Allocation of Resources Without Limits or Throttling
CVE-2026-84170 is a high-severity allocation of resources without limits or throttling vulnerability in Apache Wicket from Apache, with a CVSS 4.0 base score of 8.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache Wicket versions: 9.14.0 through 9.24.0; 10.0.0 through 10.9.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Apache Wicket you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Wicket | 9.14.0 through 9.24.0; 10.0.0 through 10.9.1 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- NoneNo loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- LowLimited loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/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. Scored by CNA (apache.org).
Official 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: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Allocation of Resources Without Limits or Throttling
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.
How developers prevent this class of flaw
- Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
- Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Apache Wicket
- 7.6 High severity
- 7.4 High severity
- 8.3 High severity
- 7.4 High severity
- 7.4 High severity
- 7.6 High severity
Recent Allocation of Resources Without Limits or Throttling vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
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