CVE-2026-101269 in pretix
Summary
by MITRE • 09/29/2026
The mechanism binding API-uploaded files to the uploader's authentication method is not working correctly and the same session token is used for all token-based API users. Since API-uploaded files are refered to by randomly generated UUIDs and only exist for a day, there is virtually no risk, but it renders the added protection mechanism useless.
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability described constitutes a critical failure in access control mechanisms within an application's file upload subsystem, specifically affecting API-based interactions. The core technical flaw lies in the authentication binding logic, where the system fails to correctly associate uploaded files with the specific authenticated user session that initiated the request. Instead of generating unique session tokens or validating per-user credentials for each upload operation, the implementation erroneously utilizes a single shared session token across all users who authenticate via API keys or similar methods. This represents a fundamental breakdown in identity verification during state-changing operations, allowing any authorized API consumer to potentially influence resources intended for other distinct entities within the same system context.
From a technical perspective, this issue aligns with CWE-284 Improper Access Control and CWE-613 Insufficient Session Expiration or Invalidation if the shared token persists across different logical sessions without proper isolation. The mechanism relies on UUIDs to reference uploaded files, which provides a degree of obscurity but does not constitute security by design when combined with flawed authentication binding. While the use of randomly generated identifiers prevents direct enumeration attacks against specific file locations, it does not mitigate the risk posed by the shared session token if that token grants elevated privileges or allows modification of metadata associated with other users' uploads. The operational impact is theoretically limited due to the ephemeral nature of these files, which are configured to expire and be deleted after twenty-four hours. This temporal constraint significantly reduces the window of opportunity for an attacker to exploit the vulnerability for persistent data theft or long-term system compromise.
However, the presence of this flaw renders additional protective layers ineffective, creating a false sense of security within the application's defense-in-depth strategy. Even though the immediate risk is described as virtually non-existent due to the short lifespan and random naming convention, such vulnerabilities often indicate deeper architectural issues in how session management and user context are handled throughout the API ecosystem. An attacker could potentially leverage this shared token behavior to perform actions beyond simple file uploads if other endpoints rely on similar flawed authentication logic. Furthermore, it may allow for subtle data correlation or timing attacks that do not require direct access to the content of the files but rather exploit the metadata or processing side effects associated with them.
To mitigate this vulnerability and restore proper security controls, developers must enforce strict per-user session isolation for all API endpoints involved in file handling operations. This involves ensuring that each upload request is authenticated using unique credentials or tokens tied specifically to the requesting user's identity, preventing cross-user context confusion. Implementing robust input validation and verifying ownership of resources before processing uploads can further harden this area. Additionally, reviewing other parts of the application for similar session management flaws is recommended, as isolated instances of improper access control often suggest systemic weaknesses in authentication architecture. Regular security audits focusing on CWE-284 compliance will help ensure that future developments maintain strict separation between user identities and their associated actions within the system.