Incorrect authorization in nginx-ui - #VU152977
Published: September 30, 2026
Vulnerability identifier: #VU152977
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to invoke MCP tools classified as write operations.
The vulnerability exists due to incorrect authorization in the MCP authorization middleware when processing tools/call requests containing a valid JSON-RPC request followed by another JSON value. A remote user can submit a crafted request to invoke write-class MCP tools.
The issue affects read-scoped MCP service tokens and user sessions that have not completed secure-session step-up.
Affected software
nginx-ui
Remediation
Install security update from vendor's website.
nginx-ui - update to 2.6.2