Loop Detected

Server perspective

Use 508 when a WebDAV operation fails because the server detected an infinite loop while traversing resources.

When to use

• •Return 508 when a recursive or Depth: infinity operation cannot finish due to cyclic bindings or references
• •Use it when the entire operation fails because loop detection is required to prevent unbounded traversal

How to respond

• •Track visited resources or bindings during traversal so loops are detected deterministically
• •Prefer 208 Already Reported inside Multi-Status when you can complete the response safely without repeating members

Headers to consider

• •No status-specific header is required; standard WebDAV response metadata may still apply

Response body

• •A body is recommended; explain that a cyclic reference or traversal loop was detected and include enough safe detail for operators or clients to find the offending structure

Server-side pitfalls

• •Do not use 508 for ordinary deep trees that are merely slow but not cyclic
• •Do not use 508 when duplicate suppression with 208 Already Reported would let the operation succeed

Examples