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.

Attack Vector Network

Attack Complexity Low

Privileges Required High

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
pretix unaffected
Version Status Constraints
0 affected < 2026.6.4
2026.7.0 affected < 2026.7.3
2026.8.0 affected < 2026.8.1

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Pretix Subscribe
Pretix Subscribe

Project Subscriptions

Vendors Products
Pretix Subscribe
Pretix Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://pretix.eu/about/en/blog/20261028-release-2026-8-1/ cve-icon cve-icon
History

Wed, 28 Oct 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Pretix
Pretix pretix
Vendors & Products Pretix
Pretix pretix

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'}

Projects

Sign in to view the affected projects.

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 : Deferred

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

Modified: 2026-10-28T15:24:56.033

Link: CVE-2026-101274

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T11:45:09Z

Weaknesses