CVE-2026-77518 MaxKB: Known MCP tool IDs expose owner Tool.code and can be referenced by attacker workflows
Attackers can access hidden MCP tool configurations and execute workflows using unauthorized tools due to missing authorization checks in MaxKB.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-77518?
CVE-2026-77518 is a medium-severity missing authorization vulnerability in 1Panel-dev MaxKB, published on 21 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-77518?
How do I fix CVE-2026-77518?
No fix has been published for CVE-2026-77518 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-77518 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77518 exists.
Sources
Also known as GHSA-x65c-w438-c58f.