Description
When pretix is used as the identity provider in a Single-Sign-On (SSO) setup for customer accounts, the system did not properly validate the `response_type` requested in an authorization request against the configured grant type of the SSO client. This means that if an SSO client was configured to only allow the `code` response type, which requires knowledge of the client secret to use and would wrongfully send a response type like `id_token`, it would receive back a valid token. Exploiting this requires the attacker to run JavaScript on the page specified by `redirect_uri`, which must be from a list specified in the client configuration.
Published: 2026-10-28
Score: 6.9 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Wed, 28 Oct 2026 11:45:00 +0000

Type Values Removed Values Added
Title Identity Provider Response Type Validation Bypass in SSO Leading to Token Acquisition
Weaknesses CWE-20
CWE-285

Wed, 28 Oct 2026 10:45:00 +0000

Type Values Removed Values Added
Description When pretix is used as the identity provider in a Single-Sign-On (SSO) setup for customer accounts, the system did not properly validate the `response_type` requested in an authorization request against the configured grant type of the SSO client. This means that if an SSO client was configured to only allow the `code` response type, which requires knowledge of the client secret to use and would wrongfully send a response type like `id_token`, it would receive back a valid token. Exploiting this requires the attacker to run JavaScript on the page specified by `redirect_uri`, which must be from a list specified in the client configuration.
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:L/VA:N/SC:H/SI:N/SA:N'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: pretix

Published:

Updated: 2026-10-28T10:31:23.485Z

Reserved: 2026-09-28T11:48:56.321Z

Link: CVE-2026-101274

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T11:17:13.577

Modified: 2026-10-28T11:17:13.577

Link: CVE-2026-101274

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T11:30:11Z

Weaknesses