Summary
Timing side channel vulnerability in endpoint request handler in Vaadin 15-19
Non-constant-time comparison of CSRF tokens in endpoint request handler in com.vaadin:flow-server versions 3.0.0 through 5.0.3 (Vaadin 15.0.0 through 18.0.6), and com.vaadin:fusion-endpoint version 6.0.0 (Vaadin 19.0.0) allows attacker to guess a security token for Fusion endpoints via timing attack.
Impact
GHSA-9H6G-6MXG-VVP4 has a CVSS score of 4.0 (Medium). The vector is requires local access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (19.0.1, 18.0.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
com.vaadin:vaadin-bom to 19.0.1 or later; com.vaadin:vaadin-bom to 18.0.7 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-9H6G-6MXG-VVP4? GHSA-9H6G-6MXG-VVP4 is a medium-severity security vulnerability in com.vaadin:vaadin-bom (maven), affecting versions = 19.0.0. It is fixed in 19.0.1, 18.0.7.
- How severe is GHSA-9H6G-6MXG-VVP4? GHSA-9H6G-6MXG-VVP4 has a CVSS score of 4.0 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of com.vaadin:vaadin-bom are affected by GHSA-9H6G-6MXG-VVP4? com.vaadin:vaadin-bom (maven) versions = 19.0.0 is affected.
- Is there a fix for GHSA-9H6G-6MXG-VVP4? Yes. GHSA-9H6G-6MXG-VVP4 is fixed in 19.0.1, 18.0.7. Upgrade to this version or later.
- Is GHSA-9H6G-6MXG-VVP4 exploitable, and should I be worried? Whether GHSA-9H6G-6MXG-VVP4 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-9H6G-6MXG-VVP4 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-9H6G-6MXG-VVP4?
- Upgrade
com.vaadin:vaadin-bomto 19.0.1 or later - Upgrade
com.vaadin:vaadin-bomto 18.0.7 or later
- Upgrade