Vulnerability in Rapid7 Velociraptor

CVE-2026-18636

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-18636: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18636?
CVE-2026-18636 is a medium-severity vulnerability in Rapid7 Velociraptor, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 6.8/10. Published 2026-08-11.
How severe is CVE-2026-18636?
Medium severity. CVSS v3 base score is 6.8 out of 10.