# CVE-2020-26138: FormField with square brackets in field name skips validation

Source: https://junglewise.ai/threats/cve-2020-26138-formfield-with-square-brackets-in-field-name-skips-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-03-26  
License: CC BY 4.0 with a link back

CVE-2020-26138 · Severity: low · CVSS 3.1 · Published 2022-03-26

FormField with square brackets in field name skips validation

Technologies: [silverstripe/framework (Packagist)](https://junglewise.ai/threats/technologies/silverstripe-framework). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2020-26138 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-26138 being exploited in the wild.

**How severe is CVE-2020-26138?** Low severity, with a CVSS score of 3.1, published 26 March 2022.

**Which products and versions are affected?** silverstripe/framework (Packagist) ECOSYSTEM:introduced=3.0.0,fixed=4.7.4.

**Is there a fix for CVE-2020-26138?** Yes. silverstripe/framework (Packagist): upgrade to 4.7.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2020-26138?** Check whether you run silverstripe/framework (Packagist) 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

- silverstripe/framework (Packagist): upgrade to 4.7.4 or later

  ```sh
  composer require silverstripe/framework:^4.7.4
  ```


## Affected products

- silverstripe/framework (Packagist) ECOSYSTEM:introduced=3.0.0,fixed=4.7.4

## Identifiers

- CVE-2020-26138
- GHSA-7mv4-4xpg-xq44

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- [Silverstripe Framework has a XSS vulnerability in HTML editor](https://junglewise.ai/threats/cve-2025-30148-silverstripe-framework-has-a-xss-vulnerability-in-html-editor)
- [Reflected Cross Site Scripting (XSS) in error message](https://junglewise.ai/threats/reflected-cross-site-scripting-xss-in-error-message-34236f6e)
- [Silverstripe Framework has a Reflected Cross Site Scripting (XSS) in error message](https://junglewise.ai/threats/silverstripe-framework-has-a-reflected-cross-site-scripting-xss-in-250a177b)