CVE-2026-43886 Outline: OAuth Scope Validation Logic Error Allows Privilege Escalation to Wildcard API Access
Attackers can escalate read-only OAuth tokens to full admin access by smuggling wildcard scopes due to flawed validation logic in Outline.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-43886?
CVE-2026-43886 is a high-severity vulnerability in outline, published on 11 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-269
Which versions are affected by CVE-2026-43886?
How do I fix CVE-2026-43886?
No fix has been published for CVE-2026-43886 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-43886 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43886 exists.
Sources
Also known as GHSA-7732-6qrg-wjf4.