Openwebui: >> Open Webui >> 0.8.4 Security Vulnerabilities
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.11, an internal-only bypass_filter parameter is exposed on the /openai/chat/completions and /ollama/api/chat HTTP endpoints via FastAPI query string binding, allowing any authenticated user to append ?bypass_filter=true and bypass model access control checks to invoke admin-restricted models. This vulnerability is fixed in 0.8.11.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the channel webhook create/update flow accepts arbitrary profile_image_url values, including data:image/svg+xml;base64,... payloads. The profile image endpoint then decodes and serves this SVG as image/svg+xml without sanitization, allowing attacker-controlled script handlers (for example onload) to execute when the profile-image URL is opened in the browser. This vulnerability is fixed in 0.9.3.
CVSS Score
7.4
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the audio transcription upload endpoint takes the file extension from the user-supplied filename and saves the file under CACHE_DIR/audio/transcriptions/.. The /cache/{path} route serves these files via FileResponse, which sets Content-Type from the on-disk extension and emits no Content-Disposition. A verified user with the default-on chat.stt permission can upload a polyglot WAV+HTML file named pwn.html and trick any other user into opening the resulting URL — the response comes back as text/html and any embedded <script> runs in the Open WebUI origin. This vulnerability is fixed in 0.9.3.
CVSS Score
8.7
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the POST /api/v1/notes/{id}/pin endpoint performs a write operation (toggling the is_pinned field) but only checks for read permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require write permission. This vulnerability is fixed in 0.9.3.
CVSS Score
3.5
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, an application-wide Cross-Site Request Forgery (CSRF) vulnerability was found Open-WebUl's image uploading functionality. An attacker can set an image URL to a malicious endpoint, allowing them to perform actions on behalf of a victim user. Any authenticated user can exploit this vulnerability, and any user who views the compromised image (e.g., a profile picture) will unknowingly send a GET request to the attacker-controlled URL. This can lead to cookie theft, denial of service (DoS), or other malicious actions. This vulnerability is fixed in 0.9.3.
CVSS Score
4.6
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, his advisory tracks a regression of the original Excel-preview XSS (CVE-2026-44549). The same root cause — XLSX.utils.sheet_to_html() output rendered via {@html excelHtml} without DOMPurify — was reintroduced sometime after v0.8.0 and is exploitable again This vulnerability is fixed in 0.9.3.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, a Server-Side Request Forgery (SSRF) vulnerability exists in _process_picture_url() in backend/open_webui/utils/oauth.py (line ~1338). The function fetches arbitrary URLs from OAuth picture claims without applying validate_url(), allowing an attacker to force the server to make HTTP requests to internal resources and exfiltrate the full response. This vulnerability is fixed in 0.9.0.
CVSS Score
7.7
EPSS Score
0.004
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.6, in standard channels (i.e., channels whose channel.type is neither group nor dm), the endpoint POST /api/v1/channels/{channel_id}/messages/{message_id}/update can be accessed with read permission only. When access_control is set to None, the authorization check has_access(..., type="read") evaluates to True, allowing users who are not the message owner to update messages. As a result, unauthorized modification of other users’ messages is possible. This vulnerability is fixed in 0.8.6.
CVSS Score
6.5
EPSS Score
0.003
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, a parsing difference between the urlparse and requests libraries led to an SSRF bypass vulnerability. This vulnerability is fixed in 0.9.5.
CVSS Score
8.5
EPSS Score
0.003
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the validate_url() function in backend/open_webui/retrieval/web/utils.py only validates the initial URL submitted by the caller. The HTTP clients used downstream (sync requests, async aiohttp, langchain's WebBaseLoader) follow HTTP 3xx redirects by default and do not re-validate the redirect target against the private-IP / metadata-IP block list. Any authenticated user can therefore submit a public URL that 302-redirects to an internal address (e.g. 127.0.0.1, 169.254.169.254, RFC1918) and read the internal response body via the /api/v1/retrieval/process/web endpoint, the /api/v1/images/... endpoints, the /api/chat/completions endpoint with an image_url content part, and any other route that calls these helpers. This vulnerability is fixed in 0.9.5.
CVSS Score
8.5
EPSS Score
0.003
Published
2026-05-15