# CVE-2026-18640: Velociraptor NewNotebook API directory traversal

Source: https://junglewise.ai/threats/cve-2026-18640-velociraptor-newnotebook-api-directory-traversal  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-11. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-18640 · Severity: high · CVSS 7.1 · Published 2026-08-11

Velociraptor is an endpoint visibility and response platform used by organizations to hunt for threats and collect forensic data. An authenticated user with notebook-editing permissions can exploit insufficient input validation in the NewNotebook API to write files outside the intended data directory, potentially overwriting critical metadata files like access control lists and corrupting the system's ability to manage security policies and operational data.

## Quick answers

**Is CVE-2026-18640 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18640 being exploited in the wild.

**How severe is CVE-2026-18640?** High severity, with a CVSS score of 7.1, published 11 August 2026.

**Which products and versions are affected?** Velociraptor Velociraptor before 0.77.2.

**Is there a fix for CVE-2026-18640?** A patch was published on 2026-08-11: Fixed in version 0.77.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-18640 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-18640?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The NewNotebook API fails to properly sanitize file path parameters, allowing directory traversal attacks via path sequences. An authenticated attacker with NOTEBOOK_EDIT permission can craft requests to write .json.db files outside the organization's designated data store directory, potentially overwriting sensitive metadata files including ACLs, hunts, and other system records. This vulnerability requires prior authentication and specific permissions, limiting the attack surface. Successful exploitation can cause data corruption and system instability. A patch is available in version 0.77.2 or later.

## Affected products

- Velociraptor Velociraptor before 0.77.2

## Timeline

- 2026-08-11: disclosed
- 2026-08-11: patched: Fixed in version 0.77.2

## References

- [http://docs.velociraptor.app/announcements/advisories/cve-2026-18640/](http://docs.velociraptor.app/announcements/advisories/cve-2026-18640/)