SSRF with API key leak in pretix-oppwa
Summary
| CVE | CVE-2026-13603 |
|---|---|
| State | PUBLISHED |
| Assigner | rami.io |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-01 14:16:31 UTC |
| Updated | 2026-07-02 18:43:45 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9 CRITICAL from 655498c3-6ec5-4f0b-aea6-853b334d05a6
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.002530000 probability, percentile 0.165870000 (date 2026-07-03)
Problem Types: CWE-20 | CWE-918 | CWE-20 CWE-20 Improper input validation | CWE-918 CWE-918 Server-Side request forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 655498c3-6ec5-4f0b-aea6-853b334d05a6 | Secondary | 9 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:U/C... |
| 4.0 | CNA | CVSS | 9 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:U |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Pretix | Pretix-oppwa | affected 1.4.4 python | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| pretix.eu/about/en/blog/20260701-release-2026-5-3 | 655498c3-6ec5-4f0b-aea6-853b334d05a6 | pretix.eu | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
Solutions
CNA: After installing the update, we recommend asking your payment provider for a new access token and updating it in pretix.Attack detection: If you have access logs, you can search them for resourcePath= not followed by a / or encoded slash %2F.
Workarounds
CNA: Workaround: If you are unable to update pretix quickly, we still recommend to try installing the pretix-oppwa plugin in the latest version. We have not tested it with every old pretix release, but we expect it to be compatible with any version after 2025.1. Otherwise, we recommend to uninstall the pretix-oppwa plugin.