OpenClaw's Nextcloud Talk plugin versions before 2026.2.6 incorrectly use a mutable display name field for allowlist checks, enabling an attacker to set their Nextcloud display name to any allowlisted user ID. This allows the attacker to bypass domain management and room allowlists and join conversations they should not have access to. The flaw represents a significant escalation of privilege within the application, compromising confidentiality of restricted conversations.

The vulnerability affects the OpenClaw Nextcloud Talk plugin, specifically any deployment running a version earlier than 2026.2.6.

The CVSS score of 9.3 places the flaw in the high severity range. However, the EPSS score is reported as less than 1%, indicating a very low probability of exploitation in the wild, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is remote, exploiting the plugin’s allowlist logic via a user’s display name; exploit requires legitimate authentication to the Nextcloud instance, after which the attacker can spoof a display name and gain access to protected rooms.