Is this vulnerability remotely exploitable over the network?

Yes, if the Open WebUI API is reachable over the network. However, exploitation still requires a valid authenticated user account; anonymous users cannot exploit it directly.

What level of access does an attacker need to exploit this issue?

The attacker needs any authenticated account with read access to at least one knowledge base. From there, they can discover file UUIDs and use the vulnerable endpoint to overwrite those files.

What is the safest general fix pattern for this kind of bug?

Enforce object-level authorization on all state-changing operations. For every file update or batch process request, verify that the caller has the appropriate write or ownership permission for each referenced file, rather than trusting the presence of a valid ID.

Severity:

HIGH RISK

(7.1)

Improper Authorization on File Update Endpoint (CWE-639) in Open WebUI RAG Knowledge Base

CVE-2026-28788

Published:

Mar 26, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

Remote Code Execution on the Router

April 6, 2026

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Remote Code Execution on Router Firmware

April 6, 2026

Vulnerability Type

Category:

Improper Authorization / Insecure Direct Object Reference

CWE:

CWE-639

Impact:

Unauthorized Data Modification and Integrity Compromise of RAG Knowledge Bases

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Improper Authorization / Insecure Direct Object Reference

CWE:

CWE-639

Impact:

Unauthorized Data Modification and Integrity Compromise of RAG Knowledge Bases

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

Catch This CVE While Code Is Being Written

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Improper Authorization on File Update Endpoint (CWE-639) in Open WebUI RAG Knowledge Base

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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