# CVE-2020-36320: Regular expression denial of service (ReDoS) in EmailValidator class in Vaadin 7

Source: https://junglewise.ai/threats/cve-2020-36320-regular-expression-denial-of-service-redos-in-emailvalidator  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-04-19  
License: CC BY 4.0 with a link back

CVE-2020-36320 · Severity: low · CVSS 3.1 · Published 2021-04-19

Regular expression denial of service (ReDoS) in EmailValidator class in Vaadin 7

Technologies: [com.vaadin:vaadin-bom (Maven)](https://junglewise.ai/threats/technologies/com-vaadin-vaadin-bom), [com.vaadin:vaadin-server (Maven)](https://junglewise.ai/threats/technologies/com-vaadin-vaadin-server). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2020-36320 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-36320 being exploited in the wild.

**How severe is CVE-2020-36320?** Low severity, with a CVSS score of 3.1, published 19 April 2021.

**Which products and versions are affected?** com.vaadin:vaadin-bom (Maven) ECOSYSTEM:introduced=7.0.0.beta1,fixed=7.7.22; com.vaadin:vaadin-server (Maven) ECOSYSTEM:introduced=7.0.0.beta1,fixed=7.7.22.

**Is there a fix for CVE-2020-36320?** Yes. com.vaadin:vaadin-bom (Maven): upgrade to 7.7.22 or later; com.vaadin:vaadin-server (Maven): upgrade to 7.7.22 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2020-36320?** Check whether you run com.vaadin:vaadin-bom (Maven) or com.vaadin:vaadin-server (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- com.vaadin:vaadin-bom (Maven): upgrade to 7.7.22 or later

  ```sh
  # set com.vaadin:vaadin-bom to 7.7.22 in your pom.xml or build.gradle
  ```

- com.vaadin:vaadin-server (Maven): upgrade to 7.7.22 or later

  ```sh
  # set com.vaadin:vaadin-server to 7.7.22 in your pom.xml or build.gradle
  ```


## Affected products

- com.vaadin:vaadin-bom (Maven) ECOSYSTEM:introduced=7.0.0.beta1,fixed=7.7.22
- com.vaadin:vaadin-server (Maven) ECOSYSTEM:introduced=7.0.0.beta1,fixed=7.7.22

## Identifiers

- CVE-2020-36320
- GHSA-42j4-733x-5vcf

## Related threats

- [Vaadin vulnerable to Cross-site Scripting](https://junglewise.ai/threats/cve-2025-15022-vaadin-vulnerable-to-cross-site-scripting)
- [Vaadin Framework possible file bypass via upload validation on the server-side](https://junglewise.ai/threats/cve-2025-9467-vaadin-framework-possible-file-bypass-via-upload-validation-on-the)
- [Reflected cross-site scripting in vaadin-menu-bar webjar resources in Vaadin 14](https://junglewise.ai/threats/cve-2021-33611-reflected-cross-site-scripting-in-vaadin-menu-bar-webjar)
- [Regular expression Denial of Service (ReDoS) in EmailValidator class in V7 compatibility module in Vaadin 8](https://junglewise.ai/threats/regular-expression-denial-of-service-redos-in-emailvalidator-class-in-be25bc3a)
- [Denial of service in DataCommunicator class in Vaadin 8](https://junglewise.ai/threats/denial-of-service-in-datacommunicator-class-in-vaadin-8-c2dd912d)