# CVE-2026-83621: ntopng missing authorization check in blacklist editor

Source: https://junglewise.ai/threats/cve-2026-83621-ntopng-is-a-web-based-network-traffic-monitoring-application  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-21. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-83621 · Severity: high · CVSS 8.1 · Published 2026-09-21

ntopng is a web-based network traffic monitoring tool that tracks and analyzes network activity. A flaw in the threat intelligence blacklist configuration endpoint allows any authenticated user—not just administrators—to redirect downloads to attacker-controlled servers, disable security blocklists, or stop scheduled updates. This undermines the tool's ability to detect and block known threats.

Technologies: [Ntopng](https://junglewise.ai/threats/technologies/ntopng). Vendors: [Ntop](https://junglewise.ai/threats/vendors/ntop).

## Quick answers

**Is CVE-2026-83621 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83621 being exploited in the wild.

**How severe is CVE-2026-83621?** High severity, with a CVSS score of 8.1, published 21 September 2026.

**Which products and versions are affected?** Ntopng before 6.7.260717.

**Is there a fix for CVE-2026-83621?** A patch was published on 2026-09-21: Fixed in version 6.7.260717 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-83621 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-83621?** Check whether you run Ntopng at an affected version. 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 POST /lua/rest/v2/edit/system/edit_blacklist.lua endpoint lacks an isAdministrator() check, allowing any authenticated user to call lists_utils.editList with arbitrary parameters (list_name, list_enabled, url, list_update). Changes persist via Redis and reload without lower-level authorization guards, enabling privilege escalation from user to threat-intelligence administrator. The fix adds authorization checks matching sibling endpoints.

## Affected products

- ntop ntopng before 6.7.260717

## Timeline

- 2026-09-21: disclosed
- 2026-09-21: patched: Fixed in version 6.7.260717

## References

- [https://github.com/ntop/ntopng/commit/1d0627d802c59130c82478a4eb7f14014064eae5](https://github.com/ntop/ntopng/commit/1d0627d802c59130c82478a4eb7f14014064eae5)
- [https://github.com/ntop/ntopng/commit/669589fe208fc932fe40a840e0de8e4d9df6023f](https://github.com/ntop/ntopng/commit/669589fe208fc932fe40a840e0de8e4d9df6023f)

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