Under CSAF 2.0, advisories labelled TLP:WHITE must be freely accessible, while those labelled TLP:AMBER or TLP:RED must be access protected under a separate path with automatable authentication. Unlabelled documents are served like TLP:WHITE and TLP:GREEN. Pick the label before you publish.
What TLP is doing here
The Traffic Light Protocol is a way to label how widely information may be shared. CSAF lets a document carry a distribution label, and the distribution requirements say how to serve each label. The label is a promise about handling, so it must match how you serve the file.
What the standard requires
| Label | Requirement | Serving rule |
|---|---|---|
| TLP:WHITE | 4 | Must be freely accessible |
| TLP:GREEN and unlabelled | 5 (by exclusion) | Served on the same path as TLP:WHITE |
| TLP:AMBER, TLP:RED | 5 | Must be access protected, on a different path, with TLS client authentication, access tokens or another automatable method |
Notice the word automatable. The point of CSAF is that machines fetch advisories, so a login page for humans does not meet the requirement.
Deciding what to label
Think about the audience and timing.
- Fixed and released issues that all customers should know about usually suit a public label.
- Issues under investigation that you want only affected customers to see before a fix may suit a restricted label.
- Details that would help an attacker before a patch exists should stay restricted until the fix is out.
Changing a label later means changing where the document is served. Plan the path structure so that moving a document from restricted to public is a copy plus an update, not a redesign.
A small checklist
- Do public documents live on one path and restricted ones on another?
- Can a customer's tool authenticate without a human?
- Does your provider metadata describe each feed's TLP level?
- Are documents the same facts at each level, only with different audiences?
The standard's example provider metadata includes a feed whose summary is "All TLP:WHITE advisories of Example Company", which shows the intended pattern of one feed per label.
Common slips
Two mistakes recur. The first is labelling a document restricted and then serving it from the public path, which makes the label meaningless. The second is protecting restricted documents with a browser login only, which fails the automatable authentication point. Test both paths with a plain command line client that has no browser session.
Quick check
Is TLP a legal confidentiality control?
No. It is a labelling convention. Use contracts and access controls for enforcement, and use the label to tell recipients how to handle the content.
Can we publish everything as TLP:WHITE?
Yes, if you are comfortable with it. It is the simplest approach and needs no access control.
Safeguard's policies, gates and guardrails can help enforce who sees what inside your own workflows, and the free scan checks your dependencies.
Sources
Last reviewed: 19 October 2026.
