CVE-2026-43890

7.7 HIGH
Published: May 11, 2026 Modified: May 13, 2026
View on NVD

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.7 / 10.0
EPSS (Exploit Probability)
0.2%
10th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)