Vulnerability Report

CVE-2026-34721

Title: OAuth Callback CSRF Vulnerability

Arbitrary File Access

Proof Of Concept

No public PoC currently indexed for CVE-2026-34721.

CWE Category CWE-352

Published Date Apr 08, 2026

Modified Date Jul 24, 2026

Exploit Status Not Found

Score 5.9 CVSS v4.0

Exploit Probability (EPSS)

0.15%

Vulnerability Summary

CVE-2026-34721: 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.

Impacted Vendors

zammad 1

Reference Links

https://github.com/zammad/zammad/security/advisories/GHSA-mfwp-hx66-626c

CVSS v4.0

Source Entity [email protected]

Severity MEDIUM

5.9

Attack Vector

NETWORK

Complexity

HIGH

Privileges

N/A

Interaction

PASSIVE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW VECTOR

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/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 v3.1

Source Entity [email protected]

Severity MEDIUM

6.5

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns