# CISA Locked Out of Anthropic's Mythos Preview

> Source: [https://icharles.com/articles/cisa-anthropic-mythos-preview-access](https://icharles.com/articles/cisa-anthropic-mythos-preview-access) (canonical)
> Author: iCharles News — iCharles, https://icharles.com
> Published: 2026-07-07

## TL;DR

CISA — the US agency responsible for defending critical infrastructure from cyberattacks — does not have access to Anthropic's Mythos Preview model, according to two sources who spoke to Axios. More than 40 other organizations do have access. National cyber director Sean Cairncross is currently negotiating broader civilian agency access to the model.

## Does CISA have access to Anthropic's Mythos Preview?

The Cybersecurity and Infrastructure Security Agency (**CISA**) does not have access to Anthropic's **Mythos Preview** model. Two sources told [Axios](https://www.axios.com/2026/04/21/cisa-anthropic-mythos-security) this directly. More than 40 other organizations already have access to the model.

This matters because CISA is the country's top cyber defense agency. It helps secure banks, power plants, and other critical infrastructure. Those industries are increasingly worried about AI-powered cyberattacks overwhelming their defenses.

## Why doesn't CISA have access?

The sources don't give a single explicit reason. What is clear: CISA is not on Anthropic's current access list, even though some other government agencies are using Mythos Preview.

Earlier this month, an Anthropic official told Axios the company had briefed CISA and the Commerce Department on Mythos' capabilities. A briefing is not the same as access.

The Trump administration has also spent the past year reducing capacity at CISA. It has shifted more policy influence to the White House's national cyber director and pushed some programs to the state and local level.

## Who is negotiating to change this?

National cyber director **Sean Cairncross** is among the Trump officials currently negotiating broader civilian agency access to Mythos, according to Axios.

Here's what we know so far: those negotiations are ongoing, and no deal has been reported as finalized.

## What is Mythos Preview, and who has it?

**Mythos Preview** is Anthropic's powerful new AI model currently in limited release. More than 40 organizations have been granted access. Some of those are other government agencies — but CISA is not among them.

Separately, [Nextgov/FCW](https://www.nextgov.com/cybersecurity/2026/06/hackers-breached-dhs-information-sharing-network-people-familiar-say/414534/) has reported that parts of the NSA lost access to **Mythos 5** amid an Anthropic supply chain dispute — a sign that government access to Anthropic models is uneven and contested across multiple agencies.

## What does this mean for critical infrastructure security?

Security teams at critical infrastructure organizations have historically relied on CISA to share threat intelligence across sectors. They also look to CISA to help prioritize security strategies.

Without access to Mythos Preview, CISA cannot directly evaluate the model's capabilities or use it for that threat-intelligence work. The industries it serves are already concerned about AI-powered attacks.

This situation connects to broader questions about how AI tools reach US government defenders — a topic that has also surfaced in [Anthropic's Pentagon disputes](/articles/anthropic-pentagon-claude-injunction-dispute) and in efforts like the [Palantir-NVIDIA government AI](/articles/palantir-nvidia-nemotron-sovereign-government) initiative.

## Key facts at a glance

| Detail | Status |
|---|---|
| CISA has Mythos Preview access | No |
| Organizations with Mythos Preview access | More than 40 |
| Anthropic briefed CISA on Mythos | Yes |
| Negotiating broader civilian access | Sean Cairncross, national cyber director |
| NSA Mythos 5 access | Parts of NSA lost access (supply chain dispute) |

## What happens next?

Sean Cairncross is actively negotiating broader civilian agency access to Mythos. That process is ongoing. No timeline or outcome has been confirmed in the sources.

CISA's acting director, **Nick Andersen**, appeared at a congressional hearing recently, though the sources do not detail what was said there about Mythos access specifically.

For builders and developers watching how AI tools move through government channels, this situation sits alongside other access and procurement friction — similar to the dynamics covered in our reporting on [Claude's government use](/articles/anthropic-pentagon-claude-injunction-dispute) and [sovereign government AI](/articles/palantir-nvidia-nemotron-sovereign-government) deployments.

## Frequently asked questions

**Does CISA have access to Anthropic's Mythos Preview model?**

No. Two sources told Axios that CISA is not on Anthropic's Mythos Preview access list. This is despite the fact that more than 40 other organizations — including some other government agencies — already have access to the model. Anthropic did brief CISA on Mythos' capabilities, but a briefing is not the same as access.

**How many organizations have access to Anthropic's Mythos Preview?**

More than 40 organizations have been granted access to Anthropic's Mythos Preview model, according to Axios. CISA is not among them, even though some other government agencies are included in that group.

**Who is negotiating to give CISA or other civilian agencies access to Mythos?**

National cyber director Sean Cairncross is among the Trump administration officials negotiating broader civilian agency access to Mythos Preview, according to Axios. No deal has been reported as finalized.

**Why does it matter that CISA lacks access to Mythos Preview?**

CISA is the US government's top cyber defense agency. It shares threat intelligence with banks, power plants, and other critical infrastructure operators. Those industries are concerned about AI-powered cyberattacks. Without Mythos Preview access, CISA cannot directly evaluate or use the model for that defensive work.

**Has any other government agency lost access to an Anthropic model recently?**

Yes. Nextgov/FCW reported that parts of the NSA lost access to Mythos 5 amid an Anthropic supply chain dispute. This shows that government access to Anthropic models is uneven and has faced disruption across multiple agencies, not just CISA.