# Vaadin Vulnerable to Authentication Bypass When Accessing the /VAADIN Endpoint Without a Trailing Slash Advisory record · `GHSA-rjgh-wgc7-m37j` - **Identifiers:** `GHSA-rjgh-wgc7-m37j` · `CVE-2026-2742` - **State:** Confirmed - **Severity:** CVSS 5.3 Medium - **Critical:** No - **Weakness (CWE):** [CWE-284](https://cwe.mitre.org/data/definitions/284.html) - **Tags:** [Broken access control](https://agentprime.io/advisories/tag/access-control.md) - **Published:** 10 Mar 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 10 Mar 2026, 18:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `com.vaadin:flow-server` (Maven): affected `<14.14.1 || >=23.0.0, <23.6.7 || >=24.0.0, <24.9.8 || >=25.0.0, <25.0.2`; fixed in `14.14.1`, `23.6.7`, `24.9.8`, `25.0.2` - `com.vaadin:vaadin` (Maven): affected `>=25.0.0, <25.0.2 || >=24.0.0, <24.9.8 || >=23.0.0, <23.6.7 || <14.14.1`; fixed in `25.0.2`, `24.9.8`, `23.6.7`, `14.14.1` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Vaadin (com.vaadin:flow-server and com.vaadin:vaadin) versions 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7, and 25.0.0 through 25.0.1 are affected when used with Spring Security. Requesting the /VAADIN endpoint without a trailing slash bypasses security filters, so an unauthenticated user can trigger framework initialization and create sessions. Upgrade to 14.14.1, 23.6.7, 24.9.8, 25.0.2 or newer, depending on your release line; versions 10-13 and 15-22 are no longer supported. Written 2 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 - 5.3 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/S:N/AU:Y/R:A/V:D/RE:L/U:Amber`, from CNA (Vaadin) - **CISA KEV:** Not listed. - **EPSS:** 0.0044, the 39th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:17 UTC: First seen by agentprime - 31 Oct 2026, 14:17 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-rjgh-wgc7-m37j) ## Sources - [GitHub Advisory Database: GHSA-rjgh-wgc7-m37j](https://github.com/advisories/GHSA-rjgh-wgc7-m37j) - [OSV: GHSA-rjgh-wgc7-m37j](https://osv.dev/vulnerability/GHSA-rjgh-wgc7-m37j) - - - - - - - - - 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 (), 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: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .