Outline is a service that allows for collaborative documentation. Prior to 1.7.0, ZipHelper.extract computes the extraction path for each entry by passing a full filesystem path through trimFileAndExt, a filename helper that calls path.basename on its input when truncating. When a zip entry's nested path is long enough to push the joined filesystem path over MAX_PATH_LENGTH (4096 bytes), trimFileAndExt silently drops all directory components and returns a bare filename. fs.createWriteStream then opens the file relative to the process working directory instead of inside the extraction sandbox, and the escaped file persists after import cleanup because cleanupExtractedData only removes the temporary extraction directory. This vulnerability is fixed in 1.7.0.

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, the Outline comment section permits users to mention other users; however, the backend does not validate or sanitize the href attribute associated with these mentions. As a result, potentially dangerous protocols (e.g., javascript:) are not filtered, introducing a risk of client-side code execution. This vulnerability is fixed in 1.7.0.

Outline is a service that allows for collaborative documentation. Prior to 1.7.1, the Slack integration callback for GET /auth/slack.post accepts an unsigned, session-independent OAuth state value. A third party who can obtain a Slack OAuth code for the same Outline Slack client can make a logged-in Outline user complete the callback and link that user's Outline account to the attacker's Slack team_id and user_id. The linked Slack identity can then use the Slack /outline search command as the victim Outline user. This vulnerability is fixed in 1.7.1.

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.7.0, the subscriptions.create API endpoint in server/routes/api/subscriptions/subscriptions.ts exhibits a broken authorization pattern. When both collectionId and documentId are supplied in the request, the route handler authorizes ONLY the collection branch (line 125 if (collectionId)), while the downstream subscriptionCreator command at server/commands/subscriptionCreator.ts writes the subscription against the documentId (which was never validated). The result is a subscription record pinning the attacker's user to a victim document the attacker has no read access to, on any team in the instance. The schema (server/routes/api/subscriptions/schema.ts) only enforces "at least one of collectionId/documentId" via .refine() — it does NOT enforce mutual exclusivity, so passing both is a valid, schema-conforming request. This vulnerability is fixed in 1.7.1.

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, a logic error in OAuthInterface.validateScope() uses Array.some() to validate requested OAuth scopes, causing the function to accept the entire scope array if any single scope is valid. An attacker can smuggle the wildcard * scope by requesting scope=read *, escalating a read-only OAuth token to full unrestricted API access including write, delete, and admin operations. This vulnerability is fixed in 1.7.0.

Outline is a service that allows for collaborative documentation. Prior to 1.7.0, the shares.create API accepts both collectionId and documentId simultaneously and, when published=false, only verifies read access for each—skipping the "share" permission check. A subsequent shares.update authorizes publication using an OR policy (can share collection OR can share document), so an attacker who holds share permission on one unrelated collection can publish a share that exposes an arbitrary document they cannot legitimately share, making it publicly accessible to unauthenticated users. This vulnerability is fixed in 1.7.0.

Outline is a service that allows for collaborative documentation. Prior to 1.5.0, the events.list API endpoint, used for retrieving activity logs, contains a logic flaw in its filtering mechanism. It allows any authenticated user to retrieve activity events associated with documents that have no collection (e.g., Private Drafts, Deleted Documents), regardless of the user's actual permissions on those documents. While the document content is not directly exposed, this vulnerability leaks sensitive metadata (such as Document IDs, user activity timestamps, and in some specific cases like the Document Title of Permanent Delete). Crucially, leaking valid Document IDs of deleted drafts removes the protection of UUID randomness, making High-severity IDOR attacks (such as the one identified in documents.restore) trivially exploitable by lowering the attack complexity. Version 1.5.0 fixes the issue.

Outline is a service that allows for collaborative documentation. Prior to 1.4.0, an Insecure Direct Object Reference (IDOR) vulnerability in the document restoration logic allows any team member to unauthorizedly restore, view, and seize ownership of deleted drafts belonging to other users, including administrators. By bypassing ownership validation during the restore process, an attacker can access sensitive private information and effectively lock the original owner out of their own content. Version 1.4.0 fixes the issue.