---
id: "CVE-2025-49652"
kind: "vulnerability"
aliases: ["CVE-2025-49652", "GHSA-ww28-4m4v-cq4j"]
title: "BackendAI Missing Authentication for Critical Function"
severity: "critical"
cvss: 9.8
epss: 0.00427
exploited: false
status: "open"
category: "package"
products: [{"name": "backend.ai", "fixed": ["25.15.6"], "affected": "< 25.15.6", "ecosystem": "pypi"}, {"name": "backend.ai", "fixed": ["25.19.0rc1"], "affected": ">= 25.16.0rc1, < 25.19.0rc1", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["backend.ai", "cwe-306", "package", "python", "self-hosted"]
not_affected_if: ["patched-version"]
published_at: "2025-06-09T18:15:26+00:00"
first_seen_at: "2026-10-27T15:18:30+00:00"
updated_at: "2026-10-27T15:32:59+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-ww28-4m4v-cq4j", "first_seen_at": "2026-10-27T15:18:30+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-49652", "first_seen_at": "2026-10-27T15:32:59+00:00"}]
---

# BackendAI Missing Authentication for Critical Function

Backend.AI's registration feature lacks an authentication check, so any person can create a user account. Those accounts can reach private data even when the operator has turned registration off.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- pypi:backend.ai affected < 25.15.6 fixed 25.15.6
- pypi:backend.ai affected >= 25.16.0rc1, < 25.19.0rc1 fixed 25.19.0rc1

## How to check

- Check the installed version of the `backend.ai` package with `pip show backend.ai` and compare it with the fixed versions below.
- Confirm whether registration is enabled on the deployment; the sources do not name the exact setting, so unknown.

## Fix

- Upgrade `backend.ai` to `25.15.6` on the 25.15 line, or to `25.19.0rc1` on the 25.16 to 25.19 range.
- Review user accounts created recently for ones you did not authorise, since registration may have been reachable.

## Timeline

- 2026-10-27T15:18:30+00:00 ghsa https://github.com/advisories/GHSA-ww28-4m4v-cq4j
- 2026-10-27T15:32:59+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-49652

## From the sources

Missing Authentication in the registration feature of Lablup's BackendAI allows arbitrary users to create user accounts that can access private data even when registration is disabled.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_