Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
High, CVSS 7.5amended

Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability

GHSA-5ccf-884p-4jjq

What to do

Vendor response not established. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • npm open-webui

    Affected
    <= 0.3.21
    Fixed in
    no fixed version recorded

  • PyPI open-webui

    Affected
    <= 0.3.21
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
7.5 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
No dated EPSS signal available.
Source description

As published by the source; long descriptions are shortened.

A Denial of Service (DoS) vulnerability exists in open-webui/open-webui version 0.3.21. This vulnerability affects multiple endpoints, including /ollama/models/upload, /audio/api/v1/transcriptions, and /rag/api/v1/doc. The application processes multipart boundaries without authentication, leading to resource exhaustion. By appending additional characters to the multipart boundary, an attacker can cause the server to parse each byte of the boundary, ultimately leading to service unavailability. This vulnerability can be exploited remotely, resulting in high CPU and memory usage, and rendering the service inaccessible to legitimate users.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 2 · amended ·

    Amended from ghsa record GHSA-5ccf-884p-4jjq

  2. Revision 1 · created ·

    Published from osv record GHSA-5ccf-884p-4jjq

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-5ccf-884p-4jjq

Advisory: Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability
IDs: GHSA-5ccf-884p-4jjq
Record: https://patchnext.com/advisories/ghsa-5ccf-884p-4jjq (revision 2, source checked 26 Oct 2026, 12:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm open-webui: affected <= 0.3.21
- PyPI open-webui: affected <= 0.3.21

## Suggested inspection (read-only)
- `npm ls open-webui --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `python -m pip show open-webui`: prints the installed version. Run with the environment that serves production active.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on open-webui.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-5ccf-884p-4jjq (OSV record GHSA-5ccf-884p-4jjq lists affected ranges: npm open-webui >=0 =0 <=0.3.21)
- Verified: https://github.com/advisories/GHSA-5ccf-884p-4jjq (GitHub-reviewed advisory GHSA-5ccf-884p-4jjq lists affected ranges: npm open-webui >=0 =0 <=0.3.21)

Commands are suggestions: review each one before running it.

Loading voting…