CVE-2026-34719

Zammad has a Server-side request forgery (SSRF) via webhooks

State: Published
Severity: 8.3 High
Published: Apr 8, 2026
Updated: Apr 10, 2026
Reserved: Mar 30, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	8.3 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:H/SC:L/SI:N/SA:H	GitHub_M
3.1	4.3 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N	CISA-ADP

Weaknesses

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Product	Versions
zammadzammad	< 6.5.4Affected >= 7.0.0-alpha, < 7.0.1Affected

References

https://github.com/zammad/zammad/security/advisories/GHSA-2vgc-vfh2-rw75

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