CVE-2026-77518CWE-862broken-access-control

CVE-2026-77518

Medium · published September 22, 2026

CVSS v3.1
5.0
EPSS
0%
Percentile
18.2
In the wild
Unconfirmed
What it is

MaxKB is an open-source AI assistant for enterprise. In 2.10.2-lts and earlier, a normal workspace user who knows another user's active MCP tool_id in the same workspace can retrieve the hidden tool through the tool-detail route because it does not apply the per-resource authorization used by the list route. The response includes Tool.code, which may contain MCP server configuration and headers, and an attacker who can create or edit an attacker-owned workflow can place the same foreign mcp_tool_id in a workflow mcp-node so workflow debug uses the owner's MCP configuration without verifying permission to use that tool. No fixed version is available as of this review.

The record
Technical detail
CVSS v3.1
5.0 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00270 · 18.2th percentile
Weakness
CWE-862 · Missing Authorization
Published
2026-09-22T01:17Z
References (1)
EPSS history
Timeline
  • 23 SEP 03:48Z
    EPSS moved — → 0%
    epss
  • 21 SEP 20:36Z
    MaxKB: Known MCP tool IDs expose owner Tool.code and can be referenced by attacker workflows
    cvelistv5