CVE-2026-45283

Description

A flaw was found in Nextcloud Server. An authenticated user could exploit this vulnerability to lock or unlock files belonging to other users by manipulating WebDAV (Web Distributed Authoring and Versioning) paths. This issue also led to the disclosure of lock tokens in error responses, potentially allowing attackers to remove locks set by legitimate users. The consequences include unauthorized file modification and a potential denial of service.

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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