5.7
MEDIUM CVSS 4.0
CVE-2026-23835
LobeHub Vulnerable to Improper Authorization in Presigned Upload
Description

LobeHub is an open source human-and-AI-agent network. Prior to version 1.143.3, the file upload feature in `Knowledge Base > File Upload` does not validate the integrity of the upload request, allowing users to intercept and modify the request parameters. As a result, it is possible to create arbitrary files in abnormal or unintended paths. In addition, since `lobechat.com` relies on the size parameter from the request to calculate file usage, an attacker can manipulate this value to misrepresent the actual file size, such as uploading a `1 GB` file while reporting it as `10 MB`, or falsely declaring a `10 MB` file as a `1 GB` file. By manipulating the size value provided in the client upload request, it is possible to bypass the monthly upload quota enforced by the server and continuously upload files beyond the intended storage and traffic limits. This abuse can result in a discrepancy between actual resource consumption and billing calculations, causing direct financial impact to the service operator. Additionally, exhaustion of storage or related resources may lead to degraded service availability, including failed uploads, delayed content delivery, or temporary suspension of upload functionality for legitimate users. A single malicious user can also negatively affect other users or projects sharing the same subscription plan, effectively causing an indirect denial of service (DoS). Furthermore, excessive and unaccounted-for uploads can distort monitoring metrics and overload downstream systems such as backup processes, malware scanning, and media processing pipelines, ultimately undermining overall operational stability and service reliability. Version 1.143.3 contains a patch for the issue.

INFO

Published Date :

Jan. 30, 2026, 8:16 p.m.

Last Modified :

Jan. 30, 2026, 8:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-23835 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update LobeHub to version 1.143.3 or later to fix file upload request validation and size reporting issues.
  • Update LobeHub to version 1.143.3 or later.
  • Verify file upload validation logic.
  • Ensure file size reporting is accurate.
  • Monitor resource usage and billing.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-23835.

URL Resource
https://github.com/lobehub/lobehub/security/advisories/GHSA-wrrr-8jcv-wjf5
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-23835 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-23835 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-23835 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jan. 30, 2026

    Action Type Old Value New Value
    Added Description LobeHub is an open source human-and-AI-agent network. Prior to version 1.143.3, the file upload feature in `Knowledge Base > File Upload` does not validate the integrity of the upload request, allowing users to intercept and modify the request parameters. As a result, it is possible to create arbitrary files in abnormal or unintended paths. In addition, since `lobechat.com` relies on the size parameter from the request to calculate file usage, an attacker can manipulate this value to misrepresent the actual file size, such as uploading a `1 GB` file while reporting it as `10 MB`, or falsely declaring a `10 MB` file as a `1 GB` file. By manipulating the size value provided in the client upload request, it is possible to bypass the monthly upload quota enforced by the server and continuously upload files beyond the intended storage and traffic limits. This abuse can result in a discrepancy between actual resource consumption and billing calculations, causing direct financial impact to the service operator. Additionally, exhaustion of storage or related resources may lead to degraded service availability, including failed uploads, delayed content delivery, or temporary suspension of upload functionality for legitimate users. A single malicious user can also negatively affect other users or projects sharing the same subscription plan, effectively causing an indirect denial of service (DoS). Furthermore, excessive and unaccounted-for uploads can distort monitoring metrics and overload downstream systems such as backup processes, malware scanning, and media processing pipelines, ultimately undermining overall operational stability and service reliability. Version 1.143.3 contains a patch for the issue.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-73
    Added Reference https://github.com/lobehub/lobehub/security/advisories/GHSA-wrrr-8jcv-wjf5
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 5.7
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability