5.1

CVE-2026-63208

Zammad: Microsoft Graph error logs expose partially masked OAuth access tokens

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, when a Microsoft Graph request fails, Zammad logs the error including the authentication token used to access the mailbox. The system attempts to hide this token in the log, but the masking is incomplete: for the token format Microsoft uses (JWT), only the first part is hidden, while the remaining parts remain readable in plain text. A Zammad admin with Microsoft Graph channel access can view these logs and see the partial token, which may reveal sensitive claims such as the account scope, tenant, or timing, and could assist in reconstructing the full token while it is still valid. This issue is fixed in version 7.1.2.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
Herstellerzammad
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Produkt zammad
Version < 7.1.2
Status affected
VulnDex Vulnerability Enrichment
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EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.31% 0.209
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 5.1 0 0
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:L/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
CWE-116 Improper Encoding or Escaping of Output

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

CWE-532 Insertion of Sensitive Information into Log File

The product writes sensitive information to a log file.

https://github.com/zammad/zammad/security/advisories/GHSA-qh8m-g5vr-7272
https://github.com/zammad/zammad/commit/2be46473eee405cc65b86a85d17059802e658532