CVE-2025-49652: Backend.ai BackendAI Missing Authentication For Critical Vulnerability

CRITICAL
Advisory Identifier: GHSA-ww28-4m4v-cq4j
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CVSS 9.8
CWE-306
Published
Advisory Summary

CVE-2025-49652 is a CRITICAL (CVSS 9.8) backendai missing authentication for critical vulnerability (CWE-306: Missing Authentication for Critical Function) affecting Backend.ai libraries in the PyPI ecosystem. The issue involves backendai missing authentication for critical function. Remediation is available by upgrading affected packages to version 25.15.6, 25.19.0rc1.

CVE-2025-49652 at a Glance

CVE Identifier CVE-2025-49652
GHSA Identifier GHSA-ww28-4m4v-cq4j
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-306: Missing Authentication for Critical Function
Affected Product Backend.ai
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-49652

To remediate this vulnerability, upgrade all affected Backend.ai dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

backend.ai fixed: 25.15.6 
pip install backend.ai>=25.15.6
backend.ai fixed: 25.19.0rc1 
pip install backend.ai>=25.19.0rc1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show backend.ai

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-49652, inspect your installed packages using pip:

pip show backend.ai

Analyze the terminal output to locate any version of Backend.ai in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 25.15.6), your application is affected.

Note: The pip show backend.ai command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-306: Missing Authentication for Critical Function, where the product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. In Backend.ai, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2025-49652 Affected Backend.ai Versions

2 component(s)
Fixed Versions:
25.15.625.19.0rc1
Product / Package Ecosystem Affected Versions Fixed Version
backend.ai
pypi/backend.ai
PyPI
< 25.15.6
25.15.6
backend.ai
pypi/backend.ai
PyPI
≥ 25.16.0rc1
< 25.19.0rc1
25.19.0rc1

References

NVD — CVE-2025-49652 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-49652
Security Fix Commit FIX COMMIT
https://github.com/lablup/backend.ai/commit/37fc8f70f9bad2dd01fe2e288f9006e96f9914ed
Security Fix Commit FIX COMMIT
https://github.com/lablup/backend.ai/commit/b6d3ddd9e285a7ce59722a37585b9298681eb82f
Security Fix Commit FIX COMMIT
https://github.com/lablup/backend.ai/commit/d7704f506e319acff205d91bfca6e2ca92939983
Backend.ai Source Repository REPOSITORY
https://github.com/lablup/backend.ai
Backend.ai Security Information SECURITY
https://hiddenlayer.com/sai_security_advisor/2025-05-backendai-49653
Backend.ai Security Information SECURITY
https://hiddenlayer.com/sai_security_advisor/2025-06-backendai

Frequently Asked Questions

What is CVE-2025-49652?
CVE-2025-49652 is a security vulnerability in Backend.ai involving BackendAI Missing Authentication for Critical Function under CWE-306: Missing Authentication for Critical Function.
Which Backend.ai versions are affected?
Affected versions include releases prior to 25.15.6, 25.19.0rc1 across affected packages: backend.ai.
What version fixes CVE-2025-49652?
Upgrading to 25.15.6, 25.19.0rc1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is backend.ai affected?
Yes, backend.ai is affected in releases prior to 25.15.6, 25.19.0rc1. Upgrade your dependency to 25.15.6, 25.19.0rc1 or later.
What is the CVSS score of CVE-2025-49652?
CVE-2025-49652 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-49652?
CVE-2025-49652 is classified under CWE-306: Missing Authentication for Critical Function (The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.).
How can I check PyPI dependencies for CVE-2025-49652?
Run the dependency tree command: 'pip show backend.ai'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-ww28-4m4v-cq4j",
  "modified" : "2026-01-20T18:50:59Z",
  "published" : "2025-06-09T18:32:17Z",
  "aliases" : [ "CVE-2025-49652" ],
  "summary" : "BackendAI Missing Authentication for Critical Function",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "backend.ai"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
        "fixed" : "25.15.6"
      } ]
    } ]
  }, {
    "package" : {
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    },
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      "events" : [ {
        "introduced" : "25.16.0rc1"
      }, {
        "fixed" : "25.19.0rc1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-49652"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lablup/backend.ai/commit/37fc8f70f9bad2dd01fe2e288f9006e96f9914ed"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lablup/backend.ai/commit/b6d3ddd9e285a7ce59722a37585b9298681eb82f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lablup/backend.ai/commit/d7704f506e319acff205d91bfca6e2ca92939983"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/lablup/backend.ai"
  }, {
    "type" : "WEB",
    "url" : "https://hiddenlayer.com/sai_security_advisor/2025-05-backendai-49653"
  }, {
    "type" : "WEB",
    "url" : "https://hiddenlayer.com/sai_security_advisor/2025-06-backendai"
  } ],
  "database_specific" : {
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    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-06-11T17:37:45Z",
    "nvd_published_at" : "2025-06-09T18:15:26Z"
  }
}