CVE-2021-31407

Server classes and resources exposure in OSGi applications using Vaadin 12-14 and 19

8.6 HighFix available

Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through 14.4.9), and 6.0.0 through 6.0.1 (Vaadin 19.0.0) allows attacker to access application classes and resources on the server via crafted HTTP request.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

2.38%Up 1.3 points since Apr 27, 2021

What each source reports

CVE List Score used 8.6

Server classes and resources exposure in OSGi applications using Vaadin 12-14 and 19

Record: CVE-2021-31407
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weakness: CWE-402
Updated: 2026-11-02

EUVDEUVD-2021-0734 8.6

Record: EUVD-2021-0734
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Updated: 2026-11-03

GitHub AdvisoriesGHSA-25xc-jwfq-39jw 8.6

OSGi applications using Vaadin 12-14 and 19 vulnerable to server classes and resources exposure

Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through 14.4.9), and 6.0.0 through 6.0.1 (Vaadin 19.0.0) allows attacker to access application classes and resources on the server via crafted HTTP request.

https://vaadin.com/security/cve-2021-31407

Record: GHSA-25xc-jwfq-39jw
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weakness: CWE-402, CWE-668
Updated: 2026-11-02

NVD 8.6

Record: CVE-2021-31407
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:P/I:N/A:N
Weakness: CWE-402, CWE-668
Updated: 2026-11-02

OSV 7.5

Record: CVE-2021-31407
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVGHSA-25xc-jwfq-39jw 8.6

OSGi applications using Vaadin 12-14 and 19 vulnerable to server classes and resources exposure

https://vaadin.com/security/cve-2021-31407

Record: GHSA-25xc-jwfq-39jw
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weakness: CWE-402, CWE-668
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`com.vaadin:flow-server` Maven	6.0.0 to 6.0.0	6.0.1
`com.vaadin:flow-server` Maven	1.2.0 to 2.4.7	2.4.8
`com.vaadin:flow-server` Maven	1.2.0 up to 2.4.8, plus listed versions 1.2.11.2.21.2.31.2.41.2.5 Show 45 moreShow less 1.3.01.4.01.4.11.4.21.4.31.4.41.4.51.4.61.4.71.4.82.0.02.0.12.0.102.0.112.0.122.0.132.0.142.0.152.0.162.0.172.0.182.0.192.0.22.0.32.0.42.0.52.0.62.0.72.0.82.0.92.1.02.1.0.beta22.1.12.1.22.1.32.1.42.1.52.1.62.1.72.1.82.1.92.2.02.2.0.alpha112.2.12.2.2	2.4.8
`com.vaadin:flow-server` Maven	6.0.0 up to 6.0.1	6.0.1

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, products	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-31407 is a high vulnerability (CVSS 8.6) in Flow Flow-server, published April 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.38%, the 83rd percentile. Fixed in com.vaadin:flow-server 6.0.1.

References

This page doesn't list everything

Left out here: 18 versions. The JSON record has them.