CVE-2026-18636: Velociraptor VFSGetBuffer API path deny list bypass

Published on 2026-07-31 Vulnogram
CVSS · MEDIUM · 6.8 ⁄10 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
Scoring scenario: GENERAL
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: HIGH
userInteraction: NONE
scope: CHANGED
confidentialityImpact: HIGH
integrityImpact: NONE
availabilityImpact: NONE
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.

Problem CWE-288 Authentication bypass using an alternate path or channel
Required configuration for exposure To exploit this the user must have the "reader" role on the ROOT org. 
Workarounds As documented,  the root org is more privileged than other orgs. You should only give trusted users access to the root org.
ProductAffected
Rapid7 Velociraptor on Linux
source repo
Default status is unaffected 		before 0.77.2
Credits
  • Itay Vardi
    •
References