Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability
Key facts
- Attack vector
- —
- Privileges required
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- User interaction
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- Attack complexity
- —
- Impact type
- Denial of service
- Confidentiality · integrity · availability
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- Fix status
- No fix listed
No CVSS vector from any source. Fix status from GitHub. Impact type from CWE-400.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | open-webui (npm) | up to 0.3.21 | — | No fix listed | GHSA-5ccf-884p-4jjq |
| — | open-webui (PyPI) | up to 0.3.21 | — | No fix listed | GHSA-5ccf-884p-4jjq |
- open-webui (npm) Vendor— Affected up to 0.3.21 Fixed in — No fix listed GHSA-5ccf-884p-4jjq
- open-webui (PyPI) Vendor— Affected up to 0.3.21 Fixed in — No fix listed GHSA-5ccf-884p-4jjq
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-03 Threatist record created from GHSA-5ccf-884p-4jjq
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences