How severe is CVE-2021-31405?

CVE-2021-31405 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-31405?

CVE-2021-31405 affects the following packages: com.vaadin:vaadin-bom (Maven), com.vaadin:vaadin-bom (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-31405?

Update com.vaadin:vaadin-bom to 14.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-31405 is resolved across your whole dependency graph.

How do I detect CVE-2021-31405 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.vaadin:vaadin-bom, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-31405 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2021-31405 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-31405 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-31405?

CVE-2021-31405 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 66th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-31405?

CVE-2021-31405 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-31405 published, and has it been updated?

CVE-2021-31405 was published on April 23, 2021 and was last updated on October 25, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2021-31405 — vaadin-bom

HIGHFix: vaadin/flow-components#442

CVE-2021-31405 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in com.vaadin:vaadin-bom. A fix is available for com.vaadin:vaadin-bom — see the affected versions and patch details below.

Regular expression denial of service (ReDoS) in EmailField component in Vaadin 14 and 15-17

Also known asGHSA-2wqp-jmcc-mc77

Published

Apr 23, 2021

Updated

Oct 25, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs66th percentile — riskier than 66% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-31405 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

☕com.vaadin:vaadin-bom☕com.vaadin:vaadin-bom

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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.

https://vaadin.com/security/cve-2021-31405

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.vaadin:vaadin-bom`	≥ 14.0.6&&< 14.4.4	14.4.4`com.vaadin:vaadin-bom:14.4.4`
☕Maven	`com.vaadin:vaadin-bom`	≥ 15.0.0&&< 17.0.11	17.0.11`com.vaadin:vaadin-bom:17.0.11`

Affected Products

2 products · 4 configurations

Application

flowvaadin

≥ 3.0.0 && < 4.0.3

range

Application

vaadinvaadin

≥ 15.0.0 && < 17.0.11

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.vaadin:vaadin-bom, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.vaadin:vaadin-bom to 14.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-31405 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

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. - https://vaadin.com/security/cve-2021-31405

O3 Security · Impact-Aware SCA

Is CVE-2021-31405 in your dependencies?

Find it across Maven, including transitive dependencies.

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CVSS Score

7.5/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE Classification

CWE-400Uncontrolled Resource Consumption

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Apr 23, 2021

Last updated

Oct 25, 2026

Identifiers

CVE-2021-31405

GHSA-2wqp-jmcc-mc77

References

Advisoryvaadin.com Advisorynvd.nist.gov Fixgithub.com Webgithub.com

Related vulnerabilities

This CVE is high severity; 2 of 8 other CVEs affecting vaadin-bom are rated as high or higher (top: high).

CVE-2021-33611GHSA-jfmf-w293-8xr8GHSA-hw7r-qrhp-5pffCVE-2021-33604CVE-2021-31412CVE-2021-31411CVE-2021-31408GHSA-3h5r-928v-mxhh

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 25, 2026

CVE-2021-31405 — vaadin-bom

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-31405 in your dependencies?