Apache Wicket up to 8.19.0/9.24.0/10.11.0 WebSocket Behavior WebSocketBehavior.java onMessage improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Apache Wicket up to 8.19.0/9.24.0/10.11.0. The impacted element is the function onMessage of the file org/apache/wicket/protocol/ws/api/WebSocketBehavior.java of the component WebSocket Behavior. The manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-82558. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apache Wicket up to 8.19.0/9.24.0/10.11.0. This issue affects the function onMessage of the file org/apache/wicket/protocol/ws/api/WebSocketBehavior.java of the component WebSocket Behavior. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Missing authorization in Apache Wicket. org.apache.wicket.protocol.ws.api.WebSocketBehavior, through which Wicket's native WebSocket support hands a message sent by the client to the application, calls its onMessage() callbacks without checking whether the client may invoke the component the behavior is attached to. Wicket opens a single WebSocket connection per page, and a message received on it is delivered to every WebSocketBehavior of that page. For an Ajax behavior Wicket makes this check before invoking it, through Behavior#canCallListener(Component), which refuses a component that is not visible or not enabled, including one for which the IAuthorizationStrategy denies the RENDER or ENABLE action. A WebSocketBehavior attached to such a component, or to a child of one, therefore receives the client's text and binary messages, together with a WebSocketRequestHandler that writes back to that client, where an Ajax behavior on the same component would be refused. An application is affected where it attaches a WebSocketBehavior that overrides onMessage() to a component that it hides, disables, or restricts through its IAuthorizationStrategy, for example with MetaDataRoleAuthorizationStrategy or the AuthorizeAction annotation. The client needs a session of their own and a page of their own that contains such a component: messages are delivered only to pages in the page store of the client's own session, so this gives no access to another user's session, page or connection. Messages pushed by the server are not affected. 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. Older, unsupported releases from 6.0.0 onwards are also affected. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

The advisory is shared at lists.apache.org. The identification of this vulnerability is CVE-2026-82558 since 08/29/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/02/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 8.20.0, 9.25.0 or 10.12.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-114888). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Apache

Name

• Wicket

Version

• 8.0
• 8.1
• 8.2
• 8.3
• 8.4
• 8.5
• 8.6
• 8.7
• 8.8
• 8.9
• 8.10
• 8.11
• 8.12
• 8.13
• 8.14
• 8.15
• 8.16
• 8.17
• 8.18
• 8.19.0
• 9.0
• 9.1
• 9.2
• 9.3
• 9.4
• 9.5
• 9.6
• 9.7
• 9.8
• 9.9
• 9.10
• 9.11
• 9.12
• 9.13
• 9.14
• 9.15
• 9.16
• 9.17
• 9.18
• 9.19
• 9.20
• 9.21
• 9.22
• 9.23
• 9.24.0
• 10.0
• 10.1
• 10.2
• 10.3
• 10.4
• 10.5
• 10.6
• 10.7
• 10.8
• 10.9
• 10.10
• 10.11.0

License

• open-source

Website

• Vendor: https://www.apache.org/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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