---
id: CVE-2026-101274
title: >-
  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 S…
summary: >-
  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 S…
severity: medium
cvss: 6.9
cvssVector: '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'
cvssSource: cna
vendor: pretix
product: pretix
affected:
  - pretix < 2026.6.4
  - pretix >= 2026.7.0 < 2026.7.3
  - pretix >= 2026.8.0 < 2026.8.1
published: '2026-10-28'
updated: '2026-10-28'
sourceUpdated: '2026-10-28T10:31:23.485Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-101274'
references:
  - url: 'https://pretix.eu/about/en/blog/20261028-release-2026-8-1/'
tags:
  - cve.org
ingestedAt: '2026-10-28T11:09:40.462Z'
---

## Overview

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.

## Affected

- `pretix < 2026.6.4`
- `pretix >= 2026.7.0 < 2026.7.3`
- `pretix >= 2026.8.0 < 2026.8.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.