How severe is CVE-2021-31405?

CVE-2021-31405 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-31405 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31405?

CVE-2021-31405 primarily affects Vaadin Flow. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31405?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-31405 published?

CVE-2021-31405 was published on 2021-04-23 and last updated on 2026-06-17.

CVE-2021-31405

CVE-2021-31405 is a high-severity vulnerability in Vaadin Flow with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Vaadin Flow
Published: 2021-04-23
Last modified: 2026-06-17

Description

Unsafe validation RegEx in EmailField component in com.vaadin:vaadin-text-field-flow versions 2.0.4 through 2.3.2 (Vaadin 14.0.6 through 14.4.3), and 3.0.0 through 4.0.2 (Vaadin 15.0.0 through 17.0.10) allows attackers to cause uncontrolled resource consumption by submitting malicious email addresses.

Frequently asked questions

What is CVE-2021-31405?: Unsafe validation RegEx in EmailField component in com.vaadin:vaadin-text-field-flow versions 2.0.4 through 2.3.2 (Vaadin 14.0.6 through 14.4.3), and 3.0.0 through 4.0.2 (Vaadin 15.0.0 through 17.0.10) allows attackers to cause uncontrolled resource consumption by submitting malicious email addresses.
How severe is CVE-2021-31405?: CVE-2021-31405 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-31405 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31405?: CVE-2021-31405 primarily affects Vaadin Flow. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31405?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-31405 published?: CVE-2021-31405 was published on 2021-04-23 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:vaadin:flow:*:*:*:*:*:*:*:*
cpe:2.3:a:vaadin:vaadin:*:*:*:*:*:*:*:*

More vulnerabilities in Vaadin Flow

CVE-2021-31407 — High (CVSS 8.6): Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through…
CVE-2021-31411 — Medium (CVSS 6.3): Insecure temporary directory usage in frontend build functionality of com.vaadin:flow-server versions 2.0.9 through…
CVE-2021-31408 — Medium (CVSS 6.3): Authentication.logout() helper in com.vaadin:flow-client versions 5.0.0 prior to 6.0.0 (Vaadin 18), and 6.0.0 through…
CVE-2019-25027 — Medium (CVSS 6.1): Missing output sanitization in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.10…
CVE-2020-36321 — Medium (CVSS 5.9): Improper URL validation in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.4.1 (Vaadin…
CVE-2021-31412 — Medium (CVSS 5.3): Improper sanitization of path in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through…

All CVEs affecting Vaadin Flow →

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