Medium severity · published Apr 8, 2026
CVE-2026-34718
Zammad improperly neutralizes of script-related HTML tags in ticket articles
6.1
CVSS
0.1%
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 HTML sanitizer for ticket articles was missing proper sanitization of data: ... URI schemes, resulting in storing such malicious content in the database of the Zammad instance. The Zammad GUI is rendering this content, due to applied CSP rules no harm was done by e.g., clicking such a link. This vulnerability is fixed in 7.0.1 and 6.5.4.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 4% 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-2026-34718
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34718
Vendor Advisory
https://github.com/zammad/zammad/security/advisories/GHSA-c2cf-9fc7-jhf3
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