# CVE-2021-35210: Cross site scripting in the system log

Source: https://junglewise.ai/threats/cve-2021-35210-cross-site-scripting-in-the-system-log  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-07-01  
License: CC BY 4.0 with a link back

CVE-2021-35210 · Severity: low · CVSS 3.1 · Published 2021-07-01

Cross site scripting in the system log

Technologies: [contao/contao (Packagist)](https://junglewise.ai/threats/technologies/contao-contao), [contao/core-bundle (Packagist)](https://junglewise.ai/threats/technologies/contao-core-bundle). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2021-35210 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-35210 being exploited in the wild.

**How severe is CVE-2021-35210?** Low severity, with a CVSS score of 3.1, published 1 July 2021.

**Which products and versions are affected?** contao/contao (Packagist) ECOSYSTEM:introduced=4.5.0,fixed=4.9.16; contao/core-bundle (Packagist) ECOSYSTEM:introduced=4.5.0,fixed=4.9.16.

**Is there a fix for CVE-2021-35210?** Yes. contao/contao (Packagist): upgrade to 4.9.16 or later; contao/core-bundle (Packagist): upgrade to 4.9.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-35210?** Check whether you run contao/contao (Packagist) or contao/core-bundle (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

- contao/contao (Packagist): upgrade to 4.9.16 or later

  ```sh
  composer require contao/contao:^4.9.16
  ```

- contao/core-bundle (Packagist): upgrade to 4.9.16 or later

  ```sh
  composer require contao/core-bundle:^4.9.16
  ```


## Affected products

- contao/contao (Packagist) ECOSYSTEM:introduced=4.5.0,fixed=4.9.16
- contao/core-bundle (Packagist) ECOSYSTEM:introduced=4.5.0,fixed=4.9.16

## Identifiers

- CVE-2021-35210
- GHSA-h58v-c6rf-g9f7

## Related threats

- [Contao improper access control in table access voter](https://junglewise.ai/threats/cve-2026-107851-contao-improper-access-control-in-the-table-access-voter)
- [Contao improper access control in preview links module](https://junglewise.ai/threats/cve-2026-107850-contao-improper-access-control-in-the-preview-links-module)
- [Contao: Cross-site request forgery in custom backend actions](https://junglewise.ai/threats/cve-2026-107848-contao-cross-site-request-forgery-in-custom-backend-actions)
- [Contao path traversal in images controller](https://junglewise.ai/threats/cve-2026-107844-contao-path-traversal-in-the-images-controller)
- [Contao registration module unvalidated mail resend](https://junglewise.ai/threats/cve-2026-107843-contao-the-registration-module-re-sends-activation-mails)