CVE-2026-34719
Medium
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.
SeverityMedium
CVSS4.3
Exploit probability17. percentile0.3%
Product
Zammad
PublishedApr 8, 2026
First seenApr 8, 2026
Weakness typeCWE-918Server-side request forgery (SSRF)
How to fix
Update
- zammad zammad6.5.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| zammad zammad | v < 6.5.4, 7.0.0 | 6.5.4 |
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