HTML Sanitization Flaw in Zammad Helpdesk Software
CVE-2026-34718

5.3MEDIUM

Key Information:

Vendor

Zammad

Status
Zammad
Vendor
CVE Published:
8 April 2026

What is CVE-2026-34718?

Zammad, an open-source helpdesk and customer support system, contains an HTML sanitization flaw affecting versions prior to 7.0.1 and 6.5.4. This vulnerability allows malicious content to be stored in the database due to inadequate sanitization of data within ticket articles. Although the Content Security Policy (CSP) rules help mitigate potential exploitation, the stored links could pose risks if users interact with them. Users are advised to upgrade to the latest versions to ensure protection against this type of vulnerability.

Affected Version(s)

zammad < 6.5.4 < 6.5.4

zammad >= 7.0.0-alpha, < 7.0.1 < 7.0.0-alpha, 7.0.1

References

https://github.com/zammad/zammad/security/advisories/GHSA...
x_refsource_CONFIRM

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.