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TI-2026-26963 Aliases CVE-2026-34719

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

Priority LOW 36CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
Low · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00254 16th percentileScored 2026-11-07
Fix Fixed zammad (zammad): 6.5.4, 7.0.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Zammad GmbHzammadbefore 6.5.4; 7.0.0-alpha to before 7.0.16.5.4, 7.0.1Patch availableCNA
  • zammad VendorZammad GmbH Affected before 6.5.4; 7.0.0-alpha to before 7.0.1 Fixed in 6.5.4, 7.0.1 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:*before 6.5.4VulnerableZammad GmbH
cpe:2.3:a:zammad:zammad:7.0.0:*:*:*:*:*:*:*7.0.0VulnerableZammad GmbH
  • cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:* Versions before 6.5.4 Vulnerable ·Zammad GmbH
  • cpe:2.3:a:zammad:zammad:7.0.0:*:*:*:*:*:*:* Versions 7.0.0 Vulnerable ·Zammad GmbH

Remediation

  • Fix · CNA zammad (zammad) Fixed in 6.5.4, 7.0.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34719

References

Advisory 1

  • TI-2026-65406 Local privilege escalation in Zammad v1.5.0 to v7.2.2 installed via DEB or RPM package KEVCVSS 4.0CRITICAL 9.4
  • TI-2026-65405 Undisclosed RCE in Zammad v6.3 and higher KEVCVSS 4.0CRITICAL 9.4
  • TI-2024-22252 An issue was discovered in Zammad before 6.3.0. CVSS 3.1CRITICAL 9.1
  • TI-2022-23785 A vulnerability in Zammad v5.3.0 allows attackers to execute arbitrary code or escalate… CVSS 3.1CRITICAL 9.8
  • TI-2021-18599 An issue was discovered in Zammad before 4.1.1. CVSS 3.1CRITICAL 9.8
  • TI-2021-18603 An issue was discovered in Zammad before 4.1.1. CVSS 3.1CRITICAL 9.8
See all 91 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences