Security Advisory


· Please read carefully and check if the version of your Zammad system is affected by this vulnerability. Please send us information regarding vulnerabilities in Zammad!

Security Advisory Details

  • ID: ZAA-2021-17
  • Date: 10/05/2021
  • Title: Stored XSS in User avatars
  • Severity: medium
  • Product: Zammad 1.0.x up to 4.1.0
  • Fixed in: Zammad 4.1.1, 5.0.0
  • References:
    --> CVE: CVE-2021-42085

Vulnerability Descriptions

Stored XSS in User avatars

Zammad comes with the functionality for Users to upload custom Avatars that will be shown in various places of the application. These Avatars may include malicious JavaScript code that gets blocked by a Content-Security-Policy. However, there is the possibility to upload Avatars that won't get blocked by the Content-Security-Policy.

Special 🙏 and 🤘 and ❤️ to:

This vulnerability is fixed in the latest versions of Zammad and it is recommended to upgrade to one of these.

Fixed releases can be found at:

Additional information

Online version of this advisory:

Send all remarks to security issues to

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