EXECUTIVE SUMMARY:
CVE-2026-39386 with a CVSS score of 8.8 is a critical vulnerability affecting Neko instances with versions allowing any authenticated user to obtain full administrative control of the entire Neko instance, resulting in a complete compromise of the instance. This is achieved by exploiting a lack of proper privilege assignment, modification, tracking, or checking, creating an unintended sphere of control for the authenticated user. An attacker can exploit this vulnerability by leveraging their existing authenticated session, requiring no additional privileges or user interaction, and granting them complete control over the instance's configuration, member management, room settings, broadcast control, and session termination. The successful exploitation of this vulnerability would result in a significant business impact, including full control over sensitive data and operations, potentially leading to financial loss, reputational damage, and compromised user trust. The prerequisite for exploitation is an authenticated user session, which can be obtained through legitimate means, such as user registration or login.[/subscribe_to_unlock_form]
EXECUTIVE SUMMARY:
CVE-2026-39386 with a CVSS score of 8.8 is a critical vulnerability affecting Neko instances with versions allowing any authenticated user to obtain full administrative control of the entire Neko instance, resulting in a complete compromise of the instance. This is achieved by exploiting a lack of proper privilege assignment, modification, tracking, or checking, creating an unintended sphere of control for the authenticated user. An attacker can exploit this vulnerability by leveraging their existing authenticated session, requiring no additional privileges or user interaction, and granting them complete control over the instance's configuration, member management, room settings, broadcast control, and session termination. The successful exploitation of this vulnerability would result in a significant business impact, including full control over sensitive data and operations, potentially leading to financial loss, reputational damage, and compromised user trust. The prerequisite for exploitation is an authenticated user session, which can be obtained through legitimate means, such as user registration or login.[emaillocker id="1283"]
RECOMMENDATION:
We recommend you to update Neko to version v3.0.11 or 0.0.0-20260406184107-c54bcf1ee211.
REFERENCES:
The following reports contain further technical details:
https://github.com/advisories/GHSA-2gw9-c2r2-f5qf