CVE-2026-54573
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk20th percentile — higher than 20% of all known CVEs
Summary
Outline before version 1.8.0 contains a vulnerability where the AuthenticationHelper.canAccess function uses ctx.originalUrl without stripping the URL fragment (#), allowing an attacker to bypass API key scope restrictions and escalate privileges by appending a permitted path in the fragment.
Risk Assessment
An attacker can access restricted API endpoints without proper permissions, leading to privilege escalation and potential compromise of data confidentiality or integrity.
Recommendation
Immediately update Outline to version 1.8.0 or later, which includes a fix that strips the URL fragment before scope verification.
Original NVD description (English source)
Outline is a service that allows for collaborative documentation. Prior to 1.8.0, the AuthenticationHelper.canAccess function uses ctx.originalUrl to verify if an API key or OAuth token has the required scopes for a request. It extracts the resource by splitting the URL by / and taking the last segment. However, it fails to strip the URL fragment (#). Because Koa's router uses ctx.path (which strips the fragment) for routing, an attacker can append a fragment containing a permitted path (e.g., #foo/api/documents.info) to a restricted endpoint (e.g., /api/documents.create). The router will route the request to the restricted endpoint, but canAccess will evaluate the permitted path in the fragment, bypassing the API key scope restrictions and allowing privilege escalation. This vulnerability is fixed in 1.8.0.