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Broken Access Control in MaxKB OSS URL Fetch API

Low
baixin513 published GHSA-2jmj-gwvg-3gp2 May 7, 2026

Package

MaxKB

Affected versions

<=v2.8.0

Patched versions

v2.8.1

Description

Title

Broken Access Control in MaxKB OSS URL Fetch API

Summary

MaxKB 2.8.0 and prior are vulnerable to a broken access control vulnerability in the OSS file service URL fetch API. The endpoint uses application_id from the URL path without validating ownership, allowing attackers to perform operations under other applications’ policies.

Affected products

Package: 1Panel-dev/MaxKB
Versions: ≤ 2.8.0
Patched version: 2.8.1

Details

MaxKB is an open-source AI-powered question-and-answer application.
A broken access control vulnerability exists in the /chat/api/oss/get_url endpoint.The GetUrlView.get() method directly uses the application_id parameter from the URL path and passes it to get_url_content() without verifying that the authenticated token belongs to the specified application.
The business logic loads the target application’s policy and performs URL fetch operations under that application’s context, which allows cross-application privilege bypass and breaks tenant isolation.
An authenticated attacker can supply an arbitrary application ID to access features and policies of other applications without authorization.

Patches

Update MaxKB to version 2.8.1 or apply the official fix commit.The fix enforces application ownership validation at the view layer and adds explicit authorization checks to ensure the token matches the application_id.

Severity

Low

CVE ID

CVE-2026-42337

Weaknesses

No CWEs

Credits