CVE-2026-45345: Open webui Open WebUI Missing Authorization Check Vulnerability

MODERATE
Advisory Identifier: GHSA-gm54-m39w-grjp
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CVSS 6.5
CWE-285
Published
Advisory Summary

CVE-2026-45345 is a MODERATE (CVSS 6.5) open webui missing authorization check vulnerability (CWE-285: Improper Authorization) affecting Open webui libraries in the PyPI ecosystem. The issue involves open webui missing authorization check at the model update function - models from other users can be updated. Remediation is available by upgrading affected packages to version 0.5.7.

CVE-2026-45345 at a Glance

CVE Identifier CVE-2026-45345
GHSA Identifier GHSA-gm54-m39w-grjp
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-285: Improper Authorization
Affected Product Open webui
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.5

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

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

How to Fix CVE-2026-45345

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

open-webui fixed: 0.5.7 
pip install open-webui>=0.5.7
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 open-webui

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-45345, inspect your installed packages using pip:

pip show open-webui

Analyze the terminal output to locate any version of Open webui in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.7), your application is affected.

Note: The pip show open-webui command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Open webui, 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

### Summary A user can modify another user's model even if its visibility is set to `Private`. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Open WebUI 0.5.4. ### Details / PoC The user `Victim` created a private model with the visibility set to `private`: ![grafik](https://github.com/user-attachments/assets/de057943-512b-46bf-8671-2904d55ec056) The user `Attacker` can edit this model using the following POST request: ``` POST /api/v1/models/model/update?id=aaabraaa HTTP/2 Host: domain.local //Some headers removed Te: trailers {"id":"aaabraaa","base_model_id":"gpt-4o-POC","name":"testmodel","meta":{"profile_image_url":"/static/favicon.png","description":"","capabilities":{"vision":true,"usage":false,"citations":true},"suggestion_prompts":null,"tags":[],"toolIds":["test"]},"params":{},"user_id":"565c82e6-083f-42bb-bf0f-a4e214cfb9ad","access_control":{"read":{"group_ids":[],"user_ids":[]},"write":{"group_ids":[],"user_ids":[]}},"is_active":true,"updated_at":1737314575,"created_at":1737121281} ``` Request / Response ![grafik](https://github.com/user-attachments/assets/19986403-b782-4288-b618-202b55519bb1) ### Impact A user can modify another user's model even if its visibility is set to `Private`. By changing the access permissions during editing, unauthorized access can be gained.

CVE-2026-45345 Affected Open webui Versions

1 component(s)
Fixed Versions:
0.5.7
Product / Package Ecosystem Affected Versions Fixed Version
open-webui
pypi/open-webui
PyPI
< 0.5.7
0.5.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/open-webui/open-webui/security/advisories/GHSA-gm54-m39w-grjp
NVD — CVE-2026-45345 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45345
Open webui Source Repository REPOSITORY
https://github.com/open-webui/open-webui

Frequently Asked Questions

What is CVE-2026-45345?
CVE-2026-45345 is a security vulnerability in Open webui involving Open WebUI missing authorization check at the model update function - models from other users can be updated under CWE-285: Improper Authorization.
Which Open webui versions are affected?
Affected versions include releases prior to 0.5.7 across affected packages: open-webui.
What version fixes CVE-2026-45345?
Upgrading to 0.5.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is open-webui affected?
Yes, open-webui is affected in releases prior to 0.5.7. Upgrade your dependency to 0.5.7 or later.
What is the CVSS score of CVE-2026-45345?
CVE-2026-45345 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2026-45345?
CVE-2026-45345 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check PyPI dependencies for CVE-2026-45345?
Run the dependency tree command: 'pip show open-webui'. 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-gm54-m39w-grjp",
  "modified" : "2026-05-19T15:59:21Z",
  "published" : "2026-05-14T20:21:38Z",
  "aliases" : [ "CVE-2026-45345" ],
  "summary" : "Open WebUI missing authorization check at the model update function - models from other users can be updated",
  "details" : "### Summary\nA user can modify another user's model even if its visibility is set to `Private`.\nThe finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Open WebUI 0.5.4.\n\n### Details / PoC\nThe user `Victim` created a private model with the visibility set to `private`: \n![grafik](https://github.com/user-attachments/assets/de057943-512b-46bf-8671-2904d55ec056)\n\nThe user `Attacker` can edit this model using the following POST request:\n```\nPOST /api/v1/models/model/update?id=aaabraaa HTTP/2\nHost: domain.local\n//Some headers removed\nTe: trailers\n\n{\"id\":\"aaabraaa\",\"base_model_id\":\"gpt-4o-POC\",\"name\":\"testmodel\",\"meta\":{\"profile_image_url\":\"/static/favicon.png\",\"description\":\"\",\"capabilities\":{\"vision\":true,\"usage\":false,\"citations\":true},\"suggestion_prompts\":null,\"tags\":[],\"toolIds\":[\"test\"]},\"params\":{},\"user_id\":\"565c82e6-083f-42bb-bf0f-a4e214cfb9ad\",\"access_control\":{\"read\":{\"group_ids\":[],\"user_ids\":[]},\"write\":{\"group_ids\":[],\"user_ids\":[]}},\"is_active\":true,\"updated_at\":1737314575,\"created_at\":1737121281}\n```\nRequest / Response\n![grafik](https://github.com/user-attachments/assets/19986403-b782-4288-b618-202b55519bb1)\n\n### Impact\nA user can modify another user's model even if its visibility is set to `Private`. By changing the access permissions during editing, unauthorized access can be gained.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "open-webui"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.5.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.5.6"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/open-webui/open-webui/security/advisories/GHSA-gm54-m39w-grjp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45345"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/open-webui/open-webui"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-14T20:21:38Z",
    "nvd_published_at" : "2026-05-15T22:16:54Z"
  }
}