VulnerabilityDeferred

CVE-2026-54573

Outline is a service that allows for collaborative documentation.

MEDIUM 5.3EPSS 0.50%

Does this matter?

Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 4.0: 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.50% probability · 41th percentile
CISA KEV: Not listed
Weakness: CWE-863
Source: security-advisories@github.com

References

https://github.com/outline/outline/security/advisories/GHSA-5x79-rj4g-qrh8

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.