CVE-2026-18636 Velociraptor VFSGetBuffer API path deny list bypass
Attackers can bypass path restrictions in the VFSGetBuffer API to read sensitive files or access data from other organizations.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18636?
CVE-2026-18636 is a medium-severity path traversal vulnerability in Rapid7 Velociraptor, published on 11 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
The Velociraptor gRPC API has a VFSGetBuffer endpoint which allows reading files from the datastore. To prevent users from reading sensitive files or accessing other orgs, the requested path is prefix checked against a list of denied prefixes. This prefix check can be bypassed allowing a user to access usually denied files. If the user has read permission in the ROOT org, this allows access to other orgs, in which the user may not have permission.
Weakness: CWE-288
Which versions are affected by CVE-2026-18636?
How do I fix CVE-2026-18636?
Apply the vendor's patch.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-18636 being exploited?
There is no known exploitation of CVE-2026-18636 in the wild and no public exploit code.
Sources
Also known as GHSA-96p2-wv27-6pfj.