CVE-2026-45285
Description
A flaw was found in Nextcloud. When a user shares a folder or file with a Nextcloud Team that includes an external member, the system automatically generates a public link for that external member. This link, which is not visible to the folder owner, grants the same permissions as the Team's access. An attacker who obtains this unlisted link can access, modify, delete, reshare, and download all data within the shared folder without requiring further authentication, leading to unauthorized data access and potential data manipulation.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Access control checks for specific user data or functionality can be bypassed.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Horizontal escalation of privilege is possible (one user can view/modify information of another user).
Access Control
Technical Impact: Gain Privileges or Assume Identity
Vertical escalation of privilege is possible if the user-controlled key is actually a flag that indicates administrator status, allowing the attacker to gain administrative access.
Frequently Asked Questions
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