Vulnerability · Published Apr 8, 2026 · Assigned by GitHub_M

CVE-2026-34718Zammad improperly neutralizes of script-related HTML tags in ticket articles

Medium 5.3

In plain English

A medium-severity security flaw in zammad from zammad. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.2%top 95.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
zammad	zammad	< 6.5.4>= 7.0.0-alpha, < 7.0.1

Weakness: CWE-80 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

References

https://github.com/zammad/zammad/security/advisories/GHSA-c2cf-9fc7-jhf3 x_refsource_CONFIRM