Openwebui: Security Vulnerabilities
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a 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, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affected worker. This issue is fixed in 0.11.0.
CVSS Score
6.5
EPSS Score
0.003
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.0, the DELETE /api/v1/folders/{id} handler in backend/open_webui/routers/folders.py allowed a user granted write access to a shared chat folder to permanently delete chats and messages belonging to the folder owner. The cascade following the authorization check is bound to the folder owner's id, but the subfolder check accepted any inherited write grant instead of requiring ownership or administrator status. A collaborator can destroy the owner's subtree or force-move chats out of it when delete_contents=false. This issue is fixed in 0.11.0.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, inline direct model metadata accepted client-supplied knowledge attachments without filtering them against the caller's read access. Any authenticated user who knew another user's file id could have the builtin knowledge tools return indexed chunks from that file, causing a read-only cross-user confidentiality loss while leaving knowledge-base permissions and saved workspace model validation unaffected. This issue is fixed in 0.11.0.
CVSS Score
5.3
EPSS Score
0.003
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the sync cleanup endpoint authorized write access to the knowledge base in the URL but then acted on directory and file ids supplied in the request body without checking that those objects belonged to that knowledge base. A user with write access to one knowledge base could delete directories and remove file embeddings from another knowledge base, causing documents to drop out of retrieval results and breaking chat-with-file for targeted documents without disclosing contents. This issue is fixed in 0.11.0.
CVSS Score
4.3
EPSS Score
0.002
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, automation recurrence parsing in backend/open_webui/utils/automations.py anchored minutely and hourly rules at a fixed date of 2000-01-01 and then walked forward one interval at a time to find the next run. A single FREQ=MINUTELY rule enumerates roughly a quarter-century of occurrences synchronously on the event loop that also serves scheduler, HTTP, and WebSocket traffic, and the scheduler recomputes the next run for every claimed row on each poll. This causes availability impact for every other user of the instance. This issue is fixed in 0.11.0.
CVSS Score
6.5
EPSS Score
0.004
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, the terminal WebSocket route in backend/open_webui/routers/terminals.py authenticated its own first-message JWT and never applied the verified-user role gate that get_verified_user enforces on HTTP terminal routes. An account whose role is pending, including a registered but unapproved account or an account deactivated back to pending, can open an interactive terminal session when at least one terminal server is configured and its access grants cover the account. This loses the account-approval boundary for terminal access while the HTTP terminal routes correctly reject the same account. This issue is fixed in 0.11.0.
CVSS Score
6.3
EPSS Score
0.002
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.11.0, Open WebUI resolved a hostname during URL validation and rejected private, loopback, and link-local addresses, but the HTTP clients resolved the hostname again at connection time. An authenticated attacker who controlled authoritative DNS for a submitted hostname could answer with a public address during validation and an internal one during connection, reaching cloud metadata, loopback admin APIs, or internal services through URL ingest, chat image_url fetches, image editing, or OAuth profile-picture fetches, with most paths returning the response to the attacker and the OAuth path forwarding the OAuth access token. This issue is fixed in 0.11.0.
CVSS Score
6.3
EPSS Score
0.002
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.0, the standard channel message update and delete handlers accepted any caller holding write access on the channel without checking that the caller wrote the message. Because write access is the same grant a member needs to post, any ordinary participant in a shared standard channel could rewrite or permanently delete another participant message, while group and direct message handlers enforced authorship. This issue is fixed in 0.11.0.
CVSS Score
5.4
EPSS Score
0.003
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.0 until 0.11.0, when ENABLE_OAUTH_TOKEN_EXCHANGE=True, /oauth/{provider}/token/exchange accepts a raw provider access token and validates it by calling the provider userinfo endpoint without confirming which OAuth client the token was issued to. Anyone holding an access token minted for any client registered with the same provider could exchange it for an Open WebUI session as that token user, including applications the operator does not control and has never authorized. This issue is fixed in 0.11.0.
CVSS Score
8.1
EPSS Score
0.005
Published
2026-08-04
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, DELETE /api/v1/chats/{id} cancelled a chat's in-flight tasks before checking whether the caller could delete that chat. Any authenticated user who knew another user's chat id could abort that user's running model response, title generation, or tag generation, even though the delete was refused and no chat data was deleted, modified, or disclosed. This issue is fixed in 0.11.0.
CVSS Score
3.1
EPSS Score
0.003
Published
2026-08-04