Medium severity · published Apr 8, 2026
CVE-2026-34719
Zammad has a Server-side request forgery (SSRF) via webhooks
4.3
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZA
zammad · zammad
< 6.5.4; >= 7.0.0-alpha, < 7.0.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34719
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34719
Vendor Advisory
https://github.com/zammad/zammad/security/advisories/GHSA-2vgc-vfh2-rw75
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