# Unauthorized client-side property update in UIDL request handler in Vaadin 10 and 11

Advisory record · `GHSA-3h5r-928v-mxhh`

- **Identifiers:** `GHSA-3h5r-928v-mxhh`
- **State:** Confirmed
- **Severity:** CVSS 2.6 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-754](https://cwe.mitre.org/data/definitions/754.html)
- **Tags:** [CWE-754](https://agentprime.io/advisories/tag/cwe-754.md)
- **Published:** 19 Apr 2021
- **Updated:** 2 Dec 2024
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 19 Apr 2021, 14:49 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `com.vaadin:vaadin-bom` (Maven): affected `>=10.0.0, <10.0.8 || >=11.0.0, <11.0.3`; fixed in `10.0.8`, `11.0.3`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Vaadin 10 (versions 10.0.0 through 10.0.7) and Vaadin 11 (versions 11.0.0 through 11.0.2), as shipped in the com.vaadin:flow-server package, contain a missing check in the UIDL request handler. An attacker who can send a crafted synchronization message to the application can update client-side element property values. Upgrade to Vaadin 10.0.8 or 11.0.3. The source gives few details on the exact preconditions for the attack.

Written 8 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 2.6 Low, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** No score.

## Timeline

- 31 Oct 2026, 15:12 UTC: First seen by agentprime
- 31 Oct 2026, 15:12 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-3h5r-928v-mxhh)

## Sources

- [GitHub Advisory Database: GHSA-3h5r-928v-mxhh](https://github.com/advisories/GHSA-3h5r-928v-mxhh)
- [OSV: GHSA-3h5r-928v-mxhh](https://osv.dev/vulnerability/GHSA-3h5r-928v-mxhh)
- <https://github.com/vaadin/platform/security/advisories/GHSA-3h5r-928v-mxhh>
- <https://github.com/vaadin/platform>
- <https://vaadin.com/security/cve-2018-25007>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-3h5r-928v-mxhh>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-3h5r-928v-mxhh/>. Everything for agents: <https://agentprime.io/llms.txt>.