pretix pretix-oppwa up to 1.4.3 /v1/checkouts input validation

Summaryinfo

A vulnerability was found in pretix pretix-oppwa up to 1.4.3 and classified as critical. Impacted is an unknown function of the file /v1/checkouts. Such manipulation leads to input validation. This vulnerability is uniquely identified as CVE-2026-13603. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in pretix pretix-oppwa up to 1.4.3 and classified as critical. Affected by this issue is an unknown code of the file /v1/checkouts. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. The impact remains unknown. CVE summarizes:

The payment integration pretix-oppwa provides support for the payment providers VR Payment, Hobex, and potentially others based on Oppwa's technology. The integration of Oppwa, following their official documentation, includes a step where the user is redirected from the payment provider back to our system with a query parameter like ?resourcePath=/v1/checkouts/{checkoutId}/payment in the URL. Our system is then supposed to fetch the status of the transaction from the URL given by baseUrl + resourcePath. Our plugin pretix-oppwa did so insecurely by concatenating the parameter form the URL to the base domain of the API without further validation and, critically, without a / at the end of the baseUrl. Therefore, an attacker could inject a resourcePath argument in a way that causes pretix to call a different server instead. Since the request includes the access token (API key) of the Oppwa account, this would leak the access token, giving access to data contained in the payment provider's system. This is fixed with the release today by strictly validating the given API URL. After installing the update, we recommend asking your payment provider for a new access token and updating it in pretix.

The advisory is shared for download at pretix.eu. This vulnerability is handled as CVE-2026-13603 since 06/29/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Upgrading to version 1.4.4 eliminates this vulnerability.

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Productinfo

Vendor

• pretix

Name

• pretix-oppwa

Version

• 1.4.0
• 1.4.1
• 1.4.2
• 1.4.3

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CPE 2.2info

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