Vaadin Framework up to 8.32.1 Session Locking VaadinService.requestEnd v-uiId resource consumption

Summaryinfo

A vulnerability was found in Vaadin Framework up to 8.32.1 and classified as problematic. This affects the function VaadinService.requestEnd of the component Session Locking. Executing a manipulation of the argument v-uiId can lead to resource consumption. This vulnerability is registered as CVE-2026-110803. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Vaadin Framework up to 8.32.1. It has been declared as problematic. This vulnerability affects the function VaadinService.requestEnd of the component Session Locking. The manipulation of the argument v-uiId with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

VaadinService.requestEnd() in Vaadin Framework 8 locks the session and then reads the v-uiId request parameter outside the block that releases the lock. A request carrying a non-numeric v-uiId makes Integer.parseInt throw while the session lock is held, so the lock is never released and the container thread returns to its pool still owning it. Every later request to that session then blocks forever in VaadinService.lockSession(), and repeating the request exhausts the thread pool and takes the application down. No authentication is required: a session cookie, which any client obtains with a single request, is enough. Vaadin 10 and later are not affected, because Flow releases the lock in a finally block and does not read that parameter there, and Vaadin Framework 7 is not affected either. Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include: Product version Vaadin Framework 8.16.0 - 8.32.1 Mitigation Upgrade to 8.32.2 Vaadin Framework 7 and Vaadin 10 and later do not carry this behaviour and need no upgrade for this issue. Artifacts Maven coordinates / Vulnerable versions / Fixed version com.vaadin:vaadin-server / 8.16.0 - 8.32.1 / >=8.32.2 com.vaadin:vaadin-server-mpr-jakarta / 8.18.0 - 8.32.1 / >=8.32.2

The advisory is shared for download at vaadin.com. This vulnerability was named CVE-2026-110803 since 10/14/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 8.32.2 eliminates this vulnerability.

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Productinfo

Vendor

• Vaadin

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• Framework

Version

• 8.32.0
• 8.32.1

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