AI agents use linear_createWebhook to create or update resources in Linear — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Linear environment.
This tool creates a new webhook resource, which is a reversible Write operation. However, it carries high severity because misconfigured webhooks can expose sensitive Linear data to unintended external systems, enable data exfiltration, or trigger unwanted downstream actions. An AI agent given unconstrained access could create webhooks pointing to attacker-controlled servers, making this a high-risk Write operation.
From the tool's definition Tool name is 'linear_createWebhook' and description states it will 'Create a webhook for integration events'.
Documented attack patterns abuse exactly the kind of access linear_createWebhook gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Linear, and nothing reaches the server without passing your rules. This is the rule we recommend for linear_createWebhook:
{
"version": "1",
"default": "deny",
"tools": {
"linear_createWebhook": {
"limits": [
{
"counter": "linear_createwebhook_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}linear_createWebhook stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Create a webhook for integration events. It is categorised as a Write tool in the Linear MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Linear MCP server in PolicyLayer and add a rule for linear_createWebhook: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Linear. Nothing to install.
linear_createWebhook is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the linear_createWebhook rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for linear_createWebhook. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
linear_createWebhook is provided by the Linear MCP server (tacticlaunch/mcp-linear). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 182 Linear tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
182 Linear tools catalogued and risk-classified — across an index of 42,500+ MCP servers.