Open WebUI: Cross-user file content disclosure via request-scoped direct model knowledge metadata

SummaryOpen WebUI lets a client define a model inline on a chat request instead of selecting a saved workspace model. The knowledge attached to such an inline model was used as-is, without checking that the caller can read what it points at. Any authenticated user who knows another user's file id...

PYSEC-2026-3641 Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin

Summary Any authenticated user with access to a terminal server could get script of their choosing to run in the Open WebUI origin itself. The HTML file preview rendered terminal-served files in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, and the file is serv...

PYSEC-2026-3643 Open WebUI: Cross-user file content disclosure via request-scoped direct model knowledge metadata

Summary Open WebUI lets a client define a model inline on a chat request instead of selecting a saved workspace model. The knowledge attached to such an inline model was used as-is, without checking that the caller can read what it points at. Any authenticated user who knows another user's file i...

PYSEC-2026-3645 Open WebUI: Any authenticated user can reach internal services and cloud metadata via NAT64-encoded URLs

Summary Open WebUI fetches user-supplied URLs on the server for RAG URL ingestion, URL-to-markdown conversion and web-search content retrieval, and decides whether a destination is allowed by asking whether its IP address is globally routable. That test operates on the literal IPv6 address and do...

Open WebUI: A folder write-collaborator can permanently delete the owner's chats by deleting a shared subfolder

SummaryA user granted write access to a shared chat folder could permanently delete chats and messages belonging to the folder's owner. Deleting a folder cascades into the owner's chats and the entire subfolder subtree, and the deletion handler required only write access on subfolders instead of...

Open WebUI: DNS Rebinding SSRF Bypass

SummaryOpen WebUI vetted user-supplied URLs by resolving the hostname once and rejecting private, loopback and link-local addresses, then let the HTTP client resolve that hostname again at connect time. An attacker who controls the authoritative DNS for a hostname they submit can answer with a...

PYSEC-2026-3651 Open WebUI: Client-side SSRF via unrestricted external resource loading in Vega/Vega-Lite chart rendering

Summary Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer's browser without a restricted resource loader. Any user who can place such a block where another user will see it can make that user's browser issue attacker-chosen outbound GET...

Open WebUI: Account takeover via OAuth token exchange accepting tokens issued to any client

SummaryThe OAuth token exchange endpoint accepts a raw provider access token and validates it by calling the provider's userinfo endpoint. A userinfo endpoint reports only that a token is valid, never which OAuth client it was issued to, and the endpoint performed no audience or client check of i...

CVE-2026-12339: Improper Limitation of a Pathname to a Restricted Directory

A Zip Slip vulnerability in the WebUI ISP Upgrade functionality allows arbitrary file write via a crafted archive containing directory traversal sequences. An authenticated administrator may overwrite arbitrary files on the system.Successful exploitation may allow arbitrary file to be overwritten...

PT-2026-69892

Name of the Vulnerable Software and Affected Versions WebUI ISP affected versions not specified Description A Zip Slip issue exists in the ISP Upgrade functionality of the WebUI. This occurs when the system fails to properly validate archives, allowing an authenticated administrator to perform...

PT-2026-76472

Summary A workspace tool shared with a read grant returned its full Python source to the recipient. Any authenticated non-admin who could use a shared tool could also read its source, including any user on the instance when a tool was shared publicly. Source is meant to be a writer-only tier: the...

PT-2026-76470

Summary The built-in knowledge search tools let a chat participant choose the pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file, with no time limit anywhere on that...

PT-2026-76478

Summary Open WebUI fetches user-supplied URLs on the server for RAG URL ingestion, URL-to-markdown conversion and web-search content retrieval, and decides whether a destination is allowed by asking whether its IP address is globally routable. That test operates on the literal IPv6 address and do...

PT-2026-76481

Summary A user with write access to one knowledge base could delete directories, and drop file embeddings, belonging to knowledge bases they do not control. The sync cleanup endpoint verified write access on the knowledge base named in the URL and then acted on the directory and file ids supplied...

PT-2026-76485

Summary The OAuth token exchange endpoint accepts a raw provider access token and validates it by calling the provider's userinfo endpoint. A userinfo endpoint reports only that a token is valid, never which OAuth client it was issued to, and the endpoint performed no audience or client check of...

PT-2026-76480

Summary Open WebUI vetted user-supplied URLs by resolving the hostname once and rejecting private, loopback and link-local addresses, then let the HTTP client resolve that hostname again at connect time. An attacker who controls the authoritative DNS for a hostname they submit can answer with a...

PT-2026-76486

Summary With the Playwright web loader enabled, Open WebUI opens user-submitted URLs in a real browser and validates the destination address before allowing the request. That check only ran for the top-level page request. Every other request the page issued was passed through unvalidated, so a pa...

PT-2026-76471

Summary A user granted write access to a shared chat folder could permanently delete chats and messages belonging to the folder's owner. Deleting a folder cascades into the owner's chats and the entire subfolder subtree, and the deletion handler required only write access on subfolders instead of...

PT-2026-76473

Summary DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletio...

PT-2026-76474

Summary Any authenticated user with access to a terminal server could get script of their choosing to run in the Open WebUI origin itself. The HTML file preview rendered terminal-served files in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, and the file is serv...