CVE-2021-31409

Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19

7.5 HighFix available

Unsafe validation RegEx in EmailValidator component in com.vaadin:vaadin-compatibility-server versions 8.0.0 through 8.12.4 (Vaadin versions 8.0.0 through 8.12.4) allows attackers to cause uncontrolled resource consumption by submitting malicious email addresses.

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: None
Integrity: None
Availability: High

Exploit likelihood

1.67%Up 0.8 points since May 7, 2021

What each source reports

CVE List Score used 7.5

Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19

Record: CVE-2021-31409
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

EUVDEUVD-2021-1033 7.5

Record: EUVD-2021-1033
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-c332-w4jm-55wv 7.5

Regular expression Denial of Service (ReDoS) in EmailValidator class in V7 compatibility module in Vaadin 8

Unsafe validation RegEx in EmailValidator component in com.vaadin:vaadin-compatibility-server versions 8.0.0 through 8.12.4 (Vaadin versions 8.0.0 through 8.12.4) allows attackers to cause uncontrolled resource consumption by submitting malicious email addresses.

Record: GHSA-c332-w4jm-55wv
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

NVD 7.5

Record: CVE-2021-31409
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-400
Updated: 2026-11-02

OSV 7.5

Record: CVE-2021-31409
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVGHSA-c332-w4jm-55wv 7.5

Regular expression Denial of Service (ReDoS) in EmailValidator class in V7 compatibility module in Vaadin 8

Record: GHSA-c332-w4jm-55wv
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`com.vaadin:vaadin-compatibility-server` Maven	8.0.0 up to 8.13.0	8.13.0
`com.vaadin:vaadin-compatibility-server` Maven	8.0.0 up to 8.13.0, plus listed versions 8.0.18.0.28.0.38.0.48.0.5 Show 45 moreShow less 8.0.68.0.78.1.08.1.18.1.28.1.38.1.48.1.58.1.68.1.78.1.88.10.08.10.18.10.28.10.38.10.48.10.58.11.08.11.18.11.28.11.38.12.08.12.18.12.28.12.38.12.48.2.08.2.18.3.08.3.18.3.28.3.38.4.08.4.18.4.28.4.38.4.48.4.58.5.08.5.18.5.28.6.08.6.18.6.28.6.3	8.13.0

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	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-2021-31409 is a high vulnerability (CVSS 7.5) in Vaadin, published May 4, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.67%, the 76th percentile. Fixed in com.vaadin:vaadin-compatibility-server 8.13.0.

References

This page doesn't list everything

Left out here: 17 versions. The JSON record has them.