SB20261109173 - Authorization bypass through user-controlled key in authlib

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Main Vulnerability Database SB20261109173

SB20261109173 - Authorization bypass through user-controlled key in authlib

Published: November 9, 2026

Security Bulletin ID SB20261109173
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Authorization bypass through user-controlled key (CVE-ID: N/A)

CWE-ID: CWE-639 - Authorization Bypass Through User-Controlled Key

CVSSv4: 7.4 [CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows an administrator of a trusted tenant to obtain tokens for another organization's users and read or overwrite their data.

The vulnerability exists due to subject-only user resolution without issuer binding in Authlib's explicitly enabled ID-JAG grant when multiple identity providers are trusted. An administrator of a trusted tenant can submit assertions signed with their identity provider's key for a known victim subject, using genuine credentials for a client authorized for that victim, to impersonate the victim.


Remediation

Install update from vendor's website.

References