CVE-2026-34720

Zammad has an origin validation error in SSO mechanism

2.3 Low

CVE-2026-34720 is a low vulnerability (CVSS 2.3) in Zammad, published April 8, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. No source names a fixed version.

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the SSO mechanism in Zammad was not verifying the header originates from a trusted SSO proxy/gateway before applying further actions on it. This vulnerability is fixed in 7.0.1 and 6.5.4.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.10%Up 0.1 points since Apr 9, 2026

What each source reports

CVE List Score used 2.3

Zammad has an origin validation error in SSO mechanism

Record: CVE-2026-34720
CVSS 4.0: 2.3 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-346
Updated: 2026-11-02

EUVDEUVD-2026-20560 2.3

Record: EUVD-2026-20560
CVSS 4.0: 2.3 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

NVD 2.3

Record: CVE-2026-34720
CVSS 4.0: 2.3 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-346
Updated: 2026-11-02

OSV 2.3