CVE-2026-101268 in pretix
Summary
by MITRE • 09/29/2026
If an attacker is able to convince a victim on a specially crafted link, the victim is logged in to the attacker's customer account. If the victim does not notice this, this might lead to their order details being stored into the attacker's account. The attack only works when the event is available on a different domain than the organizer page.
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Analysis
by VulDB Data Team • 09/29/2026
This vulnerability represents a critical authentication bypass and session hijacking flaw rooted in improper validation of identity providers during single sign-on processes, specifically within an OAuth or OpenID Connect implementation context. The core technical deficiency lies in the application's failure to strictly enforce state parameters or origin checks when processing authorization responses from external identity providers. When a victim clicks on a maliciously crafted link hosted on a different domain than the organizer page, the authentication flow is manipulated such that the identity provider returns an authentication token intended for the attacker's account but accepts it within the context of the victim's session due to missing or weak validation mechanisms. This allows the application to erroneously associate the victim's active browser session with the attacker's customer account credentials, effectively logging the victim into a foreign account without their explicit consent or knowledge.
The operational impact of this flaw is severe, as it directly compromises user privacy and data integrity by enabling unauthorized access to sensitive personal information. Once the victim is logged in under the attacker's identity, any subsequent actions taken within that session are attributed to the attacker's profile rather than the victim's own account. This includes the storage of order details, shipping addresses, payment methods, and other personally identifiable information into the attacker's customer record. For organizations handling e-commerce or sensitive user data, this constitutes a significant breach of confidentiality and integrity, potentially leading to regulatory penalties under frameworks such as GDPR or CCPA due to the unauthorized exposure and misattribution of personal data. Furthermore, it undermines trust in the platform's security posture, as users cannot rely on their session isolation being maintained across different domains involved in the authentication flow.
From a classification perspective, this vulnerability aligns with CWE-287, which describes Improper Authentication, specifically where identity verification is bypassed through manipulation of external services or tokens. It also relates to CWE-345, Insufficient Verification of Data Authenticity, as the application fails to verify that the authentication response corresponds to the intended user context rather than an arbitrary one provided by a malicious actor. In terms of offensive security tactics, this attack vector maps closely to MITRE ATT&CK technique T1078, Valid Accounts, where adversaries leverage legitimate credentials or session states to gain unauthorized access. Additionally, it reflects aspects of T1534, Internal Spearphishing, as the initial entry point relies on deceiving a user into clicking a link that triggers this backend logic error across domain boundaries.
Mitigation strategies must focus on strengthening the validation protocols within the authentication flow. Developers should implement strict state parameter checks to ensure that each authorization request is matched with its corresponding response, preventing replay attacks or cross-domain session confusion. It is essential to validate the origin and audience claims of tokens received from identity providers to ensure they are intended for the specific application instance and user context initiating the login. Additionally, implementing SameSite cookie attributes can help mitigate some forms of cross-site request forgery that might facilitate such manipulations, although this alone does not solve the logical flaw in token binding. Regular security audits focusing on OAuth implementations and penetration testing that simulates multi-domain authentication scenarios are critical to identifying similar weaknesses before they can be exploited by malicious actors seeking to hijack user sessions or exfiltrate sensitive data through account merging techniques.