CVE-2026-13602
HighCVSS 7.7Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
A chain of vulnerabilities was found in pretix: payment plugins (Stripe, Mollie, OPPWA, BitPay, Payone, SecuConnect, Sofort, Saferpay) do not validate session parameters beyond cryptographic signature, the redirect feature uses the same key and salt for signing as the plugins, and the admin impersonation feature allows changing user after injecting arbitrary parameters. An attacker with access to at least one event can become any backend user and access all data.
Risk Assessment
The organization is at risk of complete user account takeover and unauthorized access to sensitive data, including payment and personal information, potentially leading to privacy breaches and financial losses.
Recommendation
Immediately update pretix core and all listed payment plugins to the latest releases issued today, which enforce strict session parameter validation, use different salts for signatures, and require unguessable information for session impersonation.
Other vulnerabilities in pretix
See all- CVE-2026-57533Low
Malicious HTML content could be injected into the page pretix shows when redirection to an untrusted page occurs. Since this page has a Content-Security-Policy, this can mainly be used for phishing purposes.
- CVE-2026-13225Medium
Malicious HTML content could be injected into the email address of an order, which pretix showed without sanitization on the confirmation page for individual tickets in that order.
- CVE-2026-101274Medium
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. A client configured to only allow the `code` response type could receive back a valid token of another type, such as `id_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.
- CVE-2026-101273Medium
Some API endpoints allowed creating order payments referencing a gift card by using the auto-incremented internal ID. This ID was not checked and allowed creating payments that reference gift cards from different organizers and thereby obtaining their secret. The gift card is not charged in this case, but by then triggering a refund on the payment, one can increase the value of the gift card.
- CVE-2026-101272Low
The mechanism binding files generated during a shredding process to the authentication method is not working correctly and the same session token is used for all token-based API users. This is similar to an issue fixed in 2026.7.1 but was missed while creating the fix. Since the files are referred to by randomly generated UUIDs and only exist for a day, there is virtually no risk, but it renders the added protection mechanism useless.
- CVE-2026-5600Medium
Pretix 2025 introduces a new API endpoint that returns check-in data for all events of an organizer instead of a specific event. This allows unauthorized users to access check-in information for other events.
- CVE-2025-13742Medium
Emails sent by pretix can utilize placeholders that will be filled with customer data. If the name of the attendee contained HTML or Markdown formatting, this was rendered as HTML in the resulting email, allowing a user to inject links or other formatted text through a maliciously formatted name. Since pretix applies a strict allow list approach to allowed HTML tags, this could not be abused for XSS, but it can be used to manipulate emails for phishing.
Original NVD description (English source)
We found a chain of combining multiple weaknesses in the product that could allow an attacker to become any user in the backend and access any data: * The payment integration plugins Stripe (included in the core system), pretix-mollie, pretix-oppwa, pretix-bitpay, pretix-payone, pretix-secuconnect, pretix-sofort, and pretix-saferpay contain a code path that is intended for the transport of session parameters from a tab with isolated cookies (e.g. in the pretix widget) to a new tab. For this purpose, a set of session parameters is cryptographically signed and then passed to the new tab as a URL parameter. The plugins perform no further validation of the session parameters, other than the cryptographic signature being valid. This is fixed with the releases issued today by strictly validating that no session parameters outside of the scope of the respective plugin may be set. * An unrelated feature in the core system is used to generate redirect links that obfuscate any Referer headers for outgoing links to prevent leakage of secrets in URLs. This redirect page also requires cryptographically signed parameters. Unfortunately, it uses the same key and salt for the signature as the previously mentioned feature in the payment integration plugins. A motivated attacker with access to at least one event in the backend can trick the system into cryptographically signing arbitrary content using specially crafted links. In combination with the previous issue, the attacker could use this to set and modify arbitrary parameters on their user session by injecting the signed parameters into the feature of the payment providers. This is fixed with the releases issued today by using different salts for the signature for each plugin and feature. * A third, unrelated feature in the core system is used for admin users to act on behalf of another user, mostly for debugging purposes. With being able to insert arbitrary parameters into a session, an attacker can abuse this feature to change their session from their actual user to any user in the system by guessing a valid user ID. This is fixed with the release today by requiring unguessable information to be contained in the session of the user to switch to.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS