CVE-2026-63208

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

State
Published
Severity
5.1 Medium
Published
Sep 25, 2026
Updated
Sep 25, 2026
Reserved
Jul 15, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
4.05.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-116 Improper Encoding or Escaping of Output
  • CWE-532 Insertion of Sensitive Information into Log File

Affected Products

ProductVersions
zammadzammad
  • < 7.1.2Affected

References

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