Timing side channel vulnerability in endpoint request handler in Vaadin 15-19
Priority LOW 18CWE-208Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-208.
Summary
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.
Why it matters now
EPSS 0.00211 11th percentileScored 2026-11-07
Fix Fixed com.vaadin:flow-server (Maven): 5.0.4, 6.0.1
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Vaadin | Vaadin | 19.0.0; 15.0.0 and later | — | No fix listed | CNA |
| Vaadin | flow-server | 6.0.0; 3.0.0 and later | — | No fix listed | CNA |
| — | com.vaadin:flow-server (Maven) | 3.0.0 to before 5.0.4 | 5.0.4 | Patch available | GHSA-p7jq-v8jp-j424 |
| — | com.vaadin:flow-server (Maven) | 6.0.0 to before 6.0.1 | 6.0.1 | Patch available | GHSA-p7jq-v8jp-j424 |
- Vaadin VendorVaadin Affected 19.0.0; 15.0.0 and later Fixed in — No fix listed CNA
- flow-server VendorVaadin Affected 6.0.0; 3.0.0 and later Fixed in — No fix listed CNA
- com.vaadin:flow-server (Maven) Vendor— Affected 3.0.0 to before 5.0.4 Fixed in 5.0.4 Patch available GHSA-p7jq-v8jp-j424
- com.vaadin:flow-server (Maven) Vendor— Affected 6.0.0 to before 6.0.1 Fixed in 6.0.1 Patch available GHSA-p7jq-v8jp-j424
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:vaadin:flow:*:*:*:*:*:*:*:* | 3.0.0 to before 5.0.4 | Vulnerable | Vaadin |
| cpe:2.3:a:vaadin:flow:6.0.0:-:*:*:*:*:*:* | 6.0.0 | Vulnerable | Vaadin |
| cpe:2.3:a:vaadin:vaadin:*:*:*:*:*:*:*:* | 15.0.0 to before 18.0.7 | Vulnerable | Vaadin |
| cpe:2.3:a:vaadin:vaadin:19.0.0:-:*:*:*:*:*:* | 19.0.0 | Vulnerable | Vaadin |
- cpe:2.3:a:vaadin:flow:*:*:*:*:*:*:*:* Versions 3.0.0 to before 5.0.4 Vulnerable ·Vaadin
- cpe:2.3:a:vaadin:flow:6.0.0:-:*:*:*:*:*:* Versions 6.0.0 Vulnerable ·Vaadin
- cpe:2.3:a:vaadin:vaadin:*:*:*:*:*:*:*:* Versions 15.0.0 to before 18.0.7 Vulnerable ·Vaadin
- cpe:2.3:a:vaadin:vaadin:19.0.0:-:*:*:*:*:*:* Versions 19.0.0 Vulnerable ·Vaadin
Remediation
- Fix · GHSA-p7jq-v8jp-j424 com.vaadin:flow-server (Maven) Fixed in 5.0.4 Advisory →
- Fix · GHSA-p7jq-v8jp-j424 com.vaadin:flow-server (Maven) Fixed in 6.0.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2021-31406
- 2026-10-03 Alias added: GHSA-p7jq-v8jp-j424
References
More Vaadin Flow vulnerabilities
- TI-2021-11539 Server classes and resources exposure in OSGi applications using Vaadin 12-14 and 19 CVSS 3.1HIGH 8.6
- TI-2021-11537 Regular expression denial of service (ReDoS) in EmailField component in Vaadin 14 and 15-17 CVSS 3.1HIGH 7.5
- TI-2020-18604 Directory traversal in development mode handler in Vaadin 14 and 15-17 CVSS 3.1HIGH 7.5
- TI-2021-11543 Insecure temporary directory usage in frontend build functionality of Vaadin 14 and 15-19 CVSS 3.1HIGH 7.8
- TI-2021-11540 Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19 CVSS 3.1HIGH 7.1
- TI-2020-18602 Potential sensitive data exposure in applications using Vaadin 15 CVSS 3.1MEDIUM 6.5
Sources
- CVE-2021-31406 · CVE Program
- CVE-2021-31406 · NVD
- FIRST EPSS
- GHSA-p7jq-v8jp-j424 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences