CVE-2026-34721

EUVD-2026-20561
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the OAuth callback endpoints for Microsoft, Google, and Facebook external credentials do not validate a CSRF state parameter. This vulnerability is fixed in 7.0.1 and 6.5.4.
CSRF
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
GitHub_MCNA
5.9 MEDIUM
NETWORK
HIGH
LOW
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
zammadzammad
𝑥
< 6.5.4
CNA
Common Weakness Enumeration
References
https://github.com/zammad/zammad/security/advisories/GHSA-mfwp-hx66-626c