Quick answers
- Is CVE-2026-34721 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-34721 being exploited in the wild.
- How severe is CVE-2026-34721?
- Medium severity, with a CVSS score of 6.5, published 8 April 2026.
- Which products and versions are affected?
- Zammad < 6.5.4, >= 7.0.0-alpha, < 7.0.1.
- Is there a fix for CVE-2026-34721?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-34721 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-34721?
- Check whether you run Zammad 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.
Technical details
A Cross-Site Request Forgery (CSRF) vulnerability exists in Zammad's OAuth implementation. The application fails to validate the 'state' parameter during the OAuth callback process for Microsoft, Google, and Facebook authentication providers. An attacker can exploit this by inducing a logged-in user to visit a malicious site, which then triggers a forged request to the Zammad callback endpoint. This can result in an attacker's external identity being associated with the victim's Zammad account. The issue is resolved in versions 6.5.4 and 7.0.1 by enforcing state parameter validation across all supported OAuth providers.
Affected products
- Zammad Zammad < 6.5.4, >= 7.0.0-alpha, < 7.0.1
Timeline
- 2026-04-08: advisory: Vendor advisory published via GitHub
- 2026-04-08: disclosed: CVE published