CVE-2026-18636
Velociraptor VFSGetBuffer API path deny list bypass
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.
INFO
Published Date :
Aug. 11, 2026, 3:17 p.m.
Last Modified :
Aug. 11, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 9974b330-7714-4307-a722-5648477acda7 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update the Velociraptor gRPC API.
- Implement robust path validation for VFSGetBuffer.
- Enforce stricter prefix checks to deny access.
- Review and restrict user permissions for the ROOT org.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-18636.
| URL | Resource |
|---|---|
| http://docs.velociraptor.app/announcements/advisories/cve-2026-18636/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18636 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-18636
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-18636 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18636 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 11, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-18636', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-11T19:25:52.804927Z'} -
New CVE Received by [email protected]
Aug. 11, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/Velocidex/velociraptor/', 'vendor': 'Rapid7', 'product': 'Velociraptor', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.77.2', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N Added CWE CWE-288 Added Reference http://docs.velociraptor.app/announcements/advisories/cve-2026-18636/