What’s Vulnerable › Vulnerabilities
CVE-2026-34719: Zammad has a Server-side request forgery (SSRF) via webhooks
- Severity: medium (CVSS 4.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-08 · updated 2026-07-24
- Weakness: CWE-918
Description
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the webhook model was missing a proper validation for loop back addresses, or link-local addresses — only the URL scheme (HTTP/HTTPS) as well as the hostname was checked. This could end up in retrieving confidential metadata of cloud/hosting providers. The existing check is now extended and is applied when configuring webhooks as well as triggering webhook jobs. This vulnerability is fixed in 7.0.1 and 6.5.4.
Affected products
- zammad: before 6.5.4; 7.0.0 — fixed in 6.5.4
How to fix
Upgrade to a fixed version: zammad 6.5.4. Check the vendor advisory for mitigations.
References
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