CVE-2026-18640 Velociraptor directory traversal via the NewNotebook API
Authenticated users can exploit path traversal in the NewNotebook API to overwrite critical metadata files, causing data corruption and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18640?
CVE-2026-18640 is a high-severity path traversal vulnerability in Rapid7 Velociraptor, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The NewNotebook API does not sufficiently sanitize its parameters allowing an authenticated user with NOTEBOOK_EDIT permission to write the notebook record outside the org's data store directory. The file written must have an extension of ".json.db" but can otherwise overwrite other metadata files (such as ACL records, hunts etc). This can corrupt these files and cause data corruption.
Weakness: CWE-22
Which versions are affected by CVE-2026-18640?
How do I fix CVE-2026-18640?
No fix has been published for CVE-2026-18640 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-18640 being exploited?
There is no known exploitation of CVE-2026-18640 in the wild and no public exploit code.
Sources
Also known as GHSA-48j3-8whw-hq63.